Last first.
There's quite a few pilots of (British) warbirds who don't have military experiencce. High discipline flying (aerobatics etc) does seem to be a feature, and organisations like Shuttleworth are VERY selective.
However, a general question when you are wandering about places like DX might seem crashing, but usually gets a useful answer! Just don't ask THEM for a job, keep it general.
Lending a hand with the tough and boring hands on work is also useful with these organisations, pilots who muck in are much more popular.
Hope this helps,
Cheers