Vince calls my attention to this auction.
The significant aspect is the name "Beiderbecke" scratched out on the file card.
I just wrote to Roy Hempley, the Bachology specialist, asking him what he knows about a possible link between Bix and this trumpet. Let's see what he comes up with. Roy really knows his stuff.
Bix's Bach # 620 also had the phrase "exceptionally tight" written on the file card. Take a look