With any vintage instrument it is a question of the true condition, how hard it was played previously and if it gets past these mechanical checks, if we can get the sound that we need.
Granted, there are people that get the warm fuzzies every time the word vintage falls. There it does NOT matter what a reality check is worth.
I would say that about half of the vintage instruments that I have ever played were not worth my time or effort. Pitch, intonation, valves and tone were simply not up to snuff. I have a lot of old instruments but they are ALL PLAYERS.
I do not consider the coprion bells to be special in any way except to the marketing departments. There are simply too many truly sensational instruments based on "standard techniques".