I have a vintage sax that I've acquired and don't need: a Buescher True Tone alto sax. The serial number is 147985 which, apparently, dates it to 1923.
I can't comment on the technical aspects as I'm not a techie, but it plays beautifully apart from a slight wobble on the low B/Bb keys. Also, the middle knuckle key feels a bit spongy so it might need a spring fixing.
The tone is fantastic and it probably sounds just like it did 100 years ago.
There's a minor dent on the crook that makes no difference to its playability; other than that, I can't see any signs of damage.