Brigidmac - funny you should say that. REALLY funny. That is how this initial search began, with my GGF. Problem is, there is no record of his parents, his emigration from Germany, and his mother's name which appears on the marriage record in Scotland's People is hard to decipher. Fortunately, I am able t read some German, so have been able to peruse those records, but many were destroyed during the war. Lots of luck on my side - all records prior to 1800 in Northern Ireland, gone. A huge chunk of records in Germany, gone. What I DO know, is that his mother's last name ended in-ski (possibly -sky). That would make eastern Europe very like, and thus, a possible Jewish connection, But, why would he have left his country, leaving family behind? And would a German speaking, Jew, marry a Catholic Scot? Yet, they were the only couple to have wed in a Protestant Church. I know that a Jew would have anglicized his name (I do know that is was -ch, and later, changed to -ck by some in the family once they got to the States), but there was no Jewish mention, save for one relative. I wish I knew the real story.
His father's name was Michael, as you know. And with German names - Jewish or not - the name used for daily life, was often not their given birth name. So, Michael, might actually have been Johann Michel Friedrich, etc.. His mum's name "looks" like it's "Rosalgo." Of course, I'm thinking it has to be some form of Rosaline. But a hard -go? It's just puzzling. Again, without the exact city, German research is very tough. But if your Blochs are somehow tied in, that would be unbelievable.