Troyer Family Genealogy Forum
I'm a Troyer, too and living in switzerland. my great-grandfather was a john (johann in german) troyer born in 1875 who orginated from lienz in austria and came to live in switzerland around 1900 where he moved to rorschach (kanton st. gallen/switzerland).
we did some research on the name too and found some interesting information in the “staatsarchiv wien” the vienna states archive.
since it is customary to christen one of the sons with the name of the father I think that my great-grandfather might have a close relation to your john troyer, 1781.