ge portacolor needs some parts

[drh4683]

I just found a really nice 1973 portacolor at the curb two days ago. Everything is working very well, except the contrast control is defective. It is mounted with the drive controls as an assembly of 3 controls. The carbon has chipped off and it only works when fully advanced, which of course is to much contrast. Anyone have a spare parts portacolor or chassis? The tv is too nice not to use! Its like brand new with all original ge compactrons.