I think it's the Firesign album....
But, seriously....the arm return cam assemblies on auto tables can be real Rube Goldberg affairs; what looks 'fine' can have wear or 'sticky' issues. Yours looks like the diameter cam, it's spring, or some combi is losing its' mind...
....has service manuals that you can sign in and download por gratis. Since your 1.3K is definitely off warranty, don't be afraid to go take a look for yourself.
Clean/oil/grease is relatively easy, but Ham Hans needs to be delicate in his endeavours. Most shops don't like to mess with vintage, since there's no $s' there. Lots of time, parts may be n/a unless one finds a donor...
Creates a bill that can rival or exceed the worth of the TT, so how attached are you to the unit becomes the question.
Time vs. trials, yet again...Good luck. *s*