This one is in decent shape and I don't see any red flags. I have asked the seller for photos of the pistons. The 4th valve doesn't have the original finger button but the other three do. Seems to include a more modern Besson case. Starting bid is $750 and the buy-it-now price is only $1,200!
SOLD FOR $1,235 (?)
https://www.ebay.com/itm/174244869177