You are right about the grips. My left grip is damaged at the bar end, but still serviceable. The correct stem for my bike is a Suntour XC, and I have a lead on that (sadly it does not have the logo button on the front of the stem). I also have a pair of correct pedals on the way (without dustcaps), but I located a pair of caps in my LBS's junk drawers that should be close enough.
I haven't pulled the seat post yet, but it looks like it may be original. Finding a San Marcos 171-2 leather saddle is not high on my to do list at the moment. An Avocet Touring 1 saddle may be easier to find and was standard on the 1985.
I am considering a repaint and new decals since the paint is in such poor condition; but job #1 will be dis-assembly, cleaning, bearing service, and locating the silver/grey housings that look like the originals.