The SML Rev C.
These horns appeared around s/n 73xx and by the end of this model's run, they had most or all of the "22 Features"1 - so much so that most of the posts I've seen say that these horns play as well as or better than the newer SML's.
The design is essentially a slight tweaking of the "Model 49" design. It IS significantly different from the pre-WWII Rev. B or Coleman Hawkins models and resembles more a Buffet than a Buescher.
It appears that SML started putting matching serial numbers on some of these horns' necks and only manufactured models with rolled tone holes.
There is a definite break in the Rev. C model chart: after s/n 78xx, some adjustment screws started appearing, as well as adjustable felts.
A sterling-silver neck was offered as an option for some horns. While this option may have continued into the Gold Medal series of horns, I've only seen evidence of this in one post on SOTW from a user with a silver neck AND BELL Marigaux alto (allegedly. He might have really had a Marigaux Eb alto clarinet). It would be logical, however, that SML did offer the silver neck on some of their other horns: SML began an association with King around 1960. King produced both the Silver-Sonic and Super 20 horns and (many of) these had sterling silver necks -- and the King Silver-Sonic had a sterling silver bell.
I've recently found a nice looking silver alto badly listed on eBay as a "Chinese Saxophone" . It doesn't seem to have the SML engraving on the right side of the bell (it may have been buffed off) -- and, like some Rev. C altos, it has a model number engraved on it: "Model 260". I don't really have any desire to lump this horn in with the Supers or "Model 49", because "260" doesn't really mean anything to me. Neck taper? I dunno.