There is a Hirsbrunner for sale local to me from 1981 (At least I believe that's correct - the serial seems to indicate '81).

I had the opportunity to play the horn last week, and it plays well, and is in exceptional condition, particularly for its age. The current owner played trombone in Pershing's Own "back in the day".

If anyone is particularly interested, I can facilitate communication with the owner - he's not much of an internet guy.