Bernie, It seems there were at least two Martin Heyls around Pittsburgh during the mid 1800s. I have seen some of the names to which you refer in old Pittsburgh Census data and wondered if your Heyl relatives were related to my distant Heyl relaives. I am descended from Magdalena Heyl, born in PA in 1834. Her parents were Martin Heyl and Catherine, both listed indirectly in old Census data as being born in Germany (Bavaria.) They are both buried in North Side Catholic Cemetary, Pittsburgh. Magdalena had a brother named Martin, born 1826 in Germany, again according to old Censuses, and died in 1886. He is buried, I believe, in St. Mary's Cemetary on Penn Ave. in Pittsburgh. I believe he was a tobaccanist in Pittsburgh. Since this Martin shows with a German birth in 1826 and his sister, Magdalena, shows with a PA birth in 1834, I conclude that the family immigrated to the US sometime during that period.
If you can figure out any connection with your family, I'd welcome the information. I have also wonderered about references to "Alsace-Lorraine" as part of my family origin, which doesn't seem to show up in any of the birth data I've been able to locate for The above referenced Heyls or my Schaub forebears.