Hello Net2Lar,
Congratulations on your lathe - a real iconic workhorse that is well loved and used by many. Getting the taper attachment is all the the good as it is evidently the rarest of the accessories.
You seem to have already made good headway with the cleanup - hard to believe it's the same taper attachment!
One thing I'd suggest is you look into electrolytic rust removal - it's simple, inexpensive, safe, and you can't overdo it as it only removes the rust, not the good metal. Most of what you see as rust on your machine is superficial and once removed and a bit of 'elbow grease' applied, you'll be amazed at the difference.
Insofar as where to go/what to do - I strongly suggest you document, document, and document again. It's easy to think "I'll remember how this goes back together." but six months later..................
A 'point & shoot' camera is your friend! It is impossible to have too many photos to help figure out how things fit.
Take it slow and easy, ask for help/direction as necessary, and you'll end up with a machine to be proud of that will do real work!