This is a longshot, but Diamondstein is part of a family mystery for me. And Philly plays a role as well. Bear with me because this is kind of confusing.
My ancestors came to the US in the 1890's from "Russia." Three different stories exist regarding where in Russia that was--Latvia, Poland or Belarus. There is considerable confusion as to our original name. The facts are as follows:
My great grandmother, Dora, is supposed to have had the maiden name of Misrach and her mother had the maiden name of Cohn. Dora had two siblings--David (possibly Robert David) and Ida. It is in their stories that a Diamondstein link is lurking.
I found a death record for Ida--she married a man named Spero in Los Angeles. Her death record indicates that her mother's maiden name was Misrach...yet she is supposed to be Dora's sister (everyone agrees on that). Ida's son, Simon's, death record indicates that his mother's maiden name was Diamondstein. So Dora and Ida, supposed sisters, are listed as having different maiden names. Ida's mother's maiden name is the same as Dora's maiden name. Ida's maiden name is supposed to be Diamondstein.
It gets more complicated. David, the brother of Ida and Dora, was named Danning. This was actually a name he adopted from a woman who taught him English. My mother remembers being told that his original name was Diamondstein! AND he settled in Philly after coming to the US from Russia (Poland?) via Argentina. His sons, however (including Harry Danning, a former baseball catcher for the NY Giants) don't remember the Diamondstein story--they remember his name as having once been Misrach.
So there are two names--Misrach and Diamondstein--that seem to be used interchangably in my family when they first came over. Poland is one of three possible places of origin and Philly is where David Danning (previously Diamondstein? Misrach?) settled before moving on to Los Angeles, where he died.
I don't know if this links in at all with what you are looking for. Even if it does, I am not sure how to make the links. If you DO link into my family, I have contacts for many people, mainly in Los Angeles. Ida and Dora first settled in Milwaukee before moving to LA to join David. As far as I know, no other Philly relatives exist, but it is possible that in Philly, the solution to the Diamondstein mystery in my family exists.