[old_tv_nut]

This is the first time I've looked at this set's schematic.
It has a crystal ringing circuit rather than a phase-locked loop, hence the need for a 3.58 amplifier and limiter. There are many tuned circuits that could affect the tint. I'd guess these were aligned as close to peak response as possible and then C507 was the final factory phase adjustment. It appears to me that there was no customer tint control, unless there was a mechanical shaft that brought the C507 adjustment to the outside.

Has anyone seen one of these in person to say?

By the way, showing the crystal as a diode symbol is a mistake.