[old_tv_nut]

Don't try to diagnose IF/Video problems with the crosshatch image. It will be way too sensitive to fine tuning, and will show normally negligible stuff strongly.

Looking at the strong overshoots on the program image - do they vary strongly with fine tuning or is a lot of it independent of fine tuning? If it's mostly varying, suspect IF tubes / alignment. If more constant with fine tuning, suspect video circuits.

If you have a way to inject baseband video, see what that looks like, to separate video circuit issues from IF.