Here are some Horizontal AFC schematics for various sets from the 1970s with
slight additions that may be helpful in stopping the flag waving or jittering you see when you play beta or VHS tapes through your vintage TV set.
https://www.dropbox.com/s/1fw8311noq...for%20VCRs.PDF
These are not absolute by any means but are suggestions that may help you
modify your sets H AFC so it is more stable.
Cliff