1983 Zenith system 3 console

[Dreamsbeard]

Hello fellow CRT nut Zombies (its halloween so why not)

Just a quick question for you today ; I brought home a 1983 zenith system 3 console with a 9-214 main board (strange as I tought that was advance system 3 board aprox 1985). The problem is, I need to touch up the grayscale but I can't find the individual screen potentiometers.

Main screen and focus are on the flyback...but where are individual gun adjustment?

Thanks!