OK... I am calling this guy Michael b/c his name showed up as such in a Pgh paper as such, tho in Hstd he was once called Morris. This is the Devai who lived in Hstd in the early 1900s/worked as a jeweler/lost his wife/joined the syn/&c. I am pretty sure he is not Martin F. or Morris J. Davidovitz/Devay, cousins of the Grossmans, but I still do not know who he is. His existence here is merely theoretical, like a subatomic particle predicted by theory but not yet discovered via experimentation.
Not in 1900, 1902 Hstd city dirs (double-checked). Double-checked a couple 1900/2 Dun books also to be sure.