Update:

Left out an "M" in the 128k's serial number; it's F4410PMM0001.

I dutifully entered it into the M0001 Registry.

I can't get to Canada anytime soon, so the fellow who lives in Ontario who knows a vintage TV repairman who is in every way except geographical distance perfect to fix my problem is indeed unfortunately ruled out due to geographical distance and its related after-effects.

I hope these other three pieces of information will complete the puzzle.

Thanks so much and have a great day!