The Rozdol family known as IF1 is headed by Hersch-Leib Pikholz and his wife Sara Rosenzweig.  According to Hersch-Leib's death certificate (27 November 1880), his parents were Izak and Feige and he was forty-five years old when he died.  (We do not have a birth record for him, although we did commision a search for any Pikholz birth records in the Lwow archives.)  Sara was pregnant when Hersch-Leib died. Hersch-Leib and Sara have a daughter Feige-Minke born in the mid or late 1850's.  They have no sons named Isak and their first grandson by that name is born in about 1885.

The Rozdol family known as IF2 is headed by the brother and sister Sara-Rivka and Nachman Pikholz (spouses are Salomon Lerner, who is actually called Pikholz on his own death certificate, and Hinde Segullim).   The relationship between Sara-Rivka and Nachman is known from their grandson Izak who lived in the US.  He knew that his father was Nachman's son and his mother was Sara-Rivka's daughter.  (Izak died in 2003.) We have several birth records for the children of Sara-Rivka and Salomon (the partial one here is for Taube, born 1879) which show Sara-Rivka's parents to be Izak and Feige or Feige-Minke.  Sara-Rivka and Salomon had a daughter Feige-Minke (1863) and Isaak (1871).  Nachman had a daughter (1858) named Feige and a son Yitzhak (born in the 1860's).   This is Nachman's death record from 1891.  It shows his age at death as 48, which means he was born 1842-3 - a bit late for someone who was a father in early 1858.  The other curious item here is that Nachman's parents are listed as Tauby and Isak.  Of course it is possible that if Nachman was indeed Isak's youngest son, then Feige may have died and Isak remarried and had Nachman with the second wife.  However, that seems unlikely seeing that Nachman named his first child Feige.  More likely is that Feige died when Nachman was very young and he raised by the second wife, so people would have known him as the son of Taube.  All that assumes that Nachman was indeed younger than Isak's other known children.  (It is also possible that Feige indeed died and that Isak married a close relative - her sister perhaps - which would explain why her name continued in the family.)

The Rozdol family known as IF3 is headed by Abraham Pikholz and Taube Krut.  According to his death certificate (14 April 1878), he was fifty-two years old and his parents were Isak and Feige-Minke.  Taube died less than a year later. We have birth records for five children (1855-1870) and a birth year (1849) for another.  We have no idea about possible descendants for four of the six.  There is an Isak (b. 1902?) who may be a grandson of Taube and Abraham.  The one daughter of Taube and Abraham whose family we know has no one named either Isak or Feige. The youngest son of Avraham and Taube indeed had a daughter Feige.)

The Rozdol family known as IF4 is headed by David Pikholz and Szerka Kawa.  According to his death certificate (15 March 1882), he was fifty-nine years old and his parents were Isak and Feige.  Szerka died in 1888. We have birth records for three sons, but do not know their families.  (In one case, we have a theory and that son had no son named Isak.  His own wife was Feige.)  Other children of David and Szerka are Scheindel-Pesche and Yitzhak, who would be older than the three for whom we have records.

We also have a 1832 birth for Pinkas, to Isak and Fayga.  I considered that this is Pinkas from the family we call .Pinchas/Rachel, but have now concluded that this is probably not the same person.  That Pinkas died 1900-1904 and records for those years are not yet available.  His death record when available should have age and parents' names, allowing us to test this theory.

Keep in mind that the first Rozdol Pikholz couple is Pinkas and Sara-Rivka.  Pinkas died about 1825.  We have documentation on two of their children, one born 1807 and one born about 1818 (died 1883 at age sixty-five).  So it is reasonable that Isak is another son, older than the other two.  It is not reasonable to assume that David (b. 1823) is a great-grandson of Pinkas, so his father Isak cannot be a grandson of Pinkas.  (That would require us to say that Pinkas and Sara-Rivka had a great-grandson only five years after they themselves had a son.)

But things are not so simple.  Here are the problems.

July 1840, Sara Rifka born to Isak and Feiga.

October 1840, Sara born to Isig and Feyga.

These two birth records are in the right place chronologically, so there is no indication of a late (re-)registration.  At only three months apart, there is no possibility that the first one died and the second one was a later child of the same couple, given the same name.  If Sara had been first, we might consider that the second registration was a name correction (to Sara-Rifka) of the first registration, but we know that the adult woman was know exclusively as Sara-Rivka, so the name could not reasonably have been corrected from Sara-Rifka to Sara.  All this almost surely requires that we have two couples both named Isak and Feige, in which case we neither can identify them nor can we know for sure which child goes with which couple.  Unless, of course, we can find a reason simply to disregard one of the birth records. However, even doing so would leave another problem.  Note that on the birth record of Taube above, we have a clear signature of Isak Pikholz both in the column at the far right (bottom) and in the third column from the left (top).  Normally, we would think that this is Sara-Rivka's father, in some honorary role.  However, Sara-Rivka and Salomon had a son named Isaak in 1871, so her father Isak cannot be alive eight years later.  Therefore, this guest must be someone else with a prominent place in the family. (I will not consider that there were two births - Sara and Sara-Rivka - both of who married men named Salomon Lerner.  That would be just too weird!) There cannot be two Isak's who are both grandsons of Pinkas and Sara-Rivka - the ages would be wrong, because it would again make David (b. 1823) a great-grandson..

So what are the possibilities?

1. Pinkas and Sara-Rivka had a son Isak who married Feige and a daughter Feige who married Isak, both families going by Pikholz.  In this case, it would appear that David, Sara-Rivka and Nachman would be descended from the Isak who died in the early 1850's, while Pinkas, Hersch-Leib, Sara (who may not have survived childhood) and maybe Abraham were from the Isak who was still alive in 1879. But of course, we can only speculate.  Sara-Rivka's guest Isak would be her uncle.
2. Pinkas and Sara-Rivka had a son Isak and a grandson Isak, both of whom married a Feige. (Or a daughter and granddaughter both Feige, or a son Isak and a granddaughter Feige ...)  Here we would assume that David, Abraham,  Sara-Rivka and Nachman would be from the elder Isak and Hersch-Leib and Sara would be from the younger one.  Pinkas could be either - from the elder by virtue of his age or from the younger based on when he used the name Isak for his own son.  Sara-Rivka's guest would probably be her first cousin.  In this scenario, Isak the uncle had children over a twenty year period (1823-1842) and died by the mid 1850's, while Isak the nephew had children over a ten year period (~1830-1840) and lived until at least 1879.  Of course, there may be later children for whom we have no record.
3. Both of the above possibilities have a problem in that Abraham, Hersch-Leib and Sara-Rivka are all identified clearly as children of Feige-Minke, not just Feige.  That would seem to require them to be siblings.  (It seems highly unlikely that two Isaks both married Feige-Minke, however since people often married relatives, it is possible that these two were cousins, both named Feige-Minke for the same person. I am assuming, nonetheless, that if there are two couples, only one of the Feiges has the double name. We could still say that there is only one couple and that the extra registration is an error.  However that would require identifying Sara-Rivka's guest and we have only one other adult Isak around at that time - Isak-Sam whose only appearance is in the birth record for his son Schaje Thalenberg (RavJG family) in 1865.