This would be new information to link given in the table above for Adam Koberstein.  I will verify this on my next trip to Phillidelphia.  On July 28, 2000 I was able to spend a little time in the Philadephia, Pennsylvania City Archives at 3101 Market Street.  I was able to locate the birth record for John Koberstein.  It showed that he was born on August 6, 1886 at Philadelphia to Adam and Anna Koberstein.  Adam was indicated as a Carpet Weaver (as far as I can read it correctly).  This confirms this part of the familial relationship theorized above.  I searched the 1893, 1894, and 1895 index for K's and did not find George Koberstein.  The cencus data given above suggests that he would have been born in those years, however I do not know for certain it was in Philadelphia.  That was just a guess.  I was further able to locate and copy the Naturalization records for Adam Koberstein.  This record confirms the approximate birth year as 1861 and his immigration from Germany.  An address of 1920 Taylor Street was given and Frederick Haslein (a friend or relative presumably) swore to Adams character and length of residence in the US as at least 5 years. Here is a map of the addresses for in Philadelphia.  It is of interest that they are close together as you would expect for a family.