Those are beautiful. I love the early Austrian design. Can't find them in the Scott's but my best google guess is they have something to do with the New Linz Cathedral.
http://en.structurae.de/structures/...?id=s0024178That appears to be it on the green stamp upper right. And those gentlemen definately look like clergy. Perhaps to commemorate the finishing of the church, and even help pay for it?
Very nice. And welcome to the forum!