Update: I got this beastie working!
As I thought, there was a spring loaded lever that pulls the tape up against a head that was gummed up.
I cleaned and lubed it, cleaned the rubber parts and it works good now!
All the rubber is in great shape for 31 years old, there was some cigarette smoke residue inside but not bad, possibly it helped preserve the rubber parts.
Now, what to do with a 40 pound, 31 year old, mono, VHS player?
