Wow. What a nicely kept RV. That dash picture still shows a clean, rich wood stain and poly, with a spotless dash. They took good care of it, didn't they?
The backfiring... I hope is not a hot spot on an exhaust valve. I've seen that a couple of times and it's a head rework. Hopefully it's just running lean.
Nobody has mentioned.... all the rubber hoses, especially anything with coolant or oil. These run hot in that little cave. Did ford run the fuel rail coolers in these to prevent vapor lock? I can't tell by the pics.
Btw- excellent photos of the parts in question... well done for us to see.
Very nice find, hows the interior, plumbing, and roof? Someone mentioned it before, the smallest leak = wood rot, very quickly. Just like boats don't age well in water, RVs don't age well outside.