Re: The conn 12m
Can you email me a picture? Is this an ebay auction? Can you email me the link? I will look into it for you. Something just smells funny to me here. The Conn 12M is a baritone saxophone. The 6M is an alto. There are also the Directors models (14M, 18M and 20M) and a few others. That Serial number would indicate that the horn was made in 1925. If that were in fact true, it would be an early New Wonder Series II. It's possible that it is an older horn that has been relacquered, and the seller is confused about the model number. If it is in fact that old, it would also have Conn's December 1914 patent date engraved near the thumbrest, along with a letters to indicate both the pitch (A=alto, B=Baritone, C=C Melody, T=Tenor, S=Soprano) and tuning (L=low pitch, H=high pitch). High pitch instruments will not play in tune with todays (low pitch) instruments, so unless you're only intending to use the horn as a decoration or to make a lamp, I would not suggest a high pitch horn.
Without seeing the horn, it's really hard to say. I've seen C Melodies advertised as Baritone horns or alto horns on ebay. Some people just have no idea what they have, or where to take it to find out. It could also be one of the later Director's model student horns.
Send me some more info and I will take a look.