let me know if you find anything on your Martin Donabauer.
i've been searching for info on my G.G. grandfather Leopold Donnerbauer for years. He was also from Austria b.1861. but more recently, i'm finding out that i THINK his name was spelled Donabauer back in his homeland, and he was more specifically from Upper Austria or lower Bohemia. so who knows...maybe our Leopolds could be related! :) Good Luck with your search!