Here's an early Mark VI tenor saxophone neck, s/n 125,xxx, made in 1965. The neck plays very well and it has a nice warm and spread sound, like a nice early Mark VI should. The neck is really the tone generator on saxophones. It makes just as much of a difference to the sound and feel of a horn as the body of the sax. Check out the color on the S logo -- it's almost black! I believe this is original and quite rare.

This neck is in good condition overall. It has had some dentwork performed in the past, but it feels very straight overall. Although the neck feels round, the lacquer pattern suggests that it suffered a very slight pulldown in the past. But if that's true, whoever performed the repair did a magnificent job, because the neck is perfectly round without a hint of a crease in the metal. 

The tenon diameter measures 27.66 mm (outside edge to outside edge), and 26.03 mm (inside edge to inside edge). Although this fits on most Mark VI saxes in my shop, it is slightly too large for a 192,xxx. This neck should work on most saxophones, but it may require a trip to your repairman to ensure a good fit with the receiver.