DMC, re; Super Sport overhaul:
My knowledge from the regulars over at bikeforums, is that for rust, oxalic acid does the trick of removing the rust. Different ways of getting oxalic acid are in deck wash from the hardware store, home depot, etc...from a chemistry supply in powder form...mix 2 percent or something like that, with water.
Guys use 000 or 0000 steel wool. Some claim aluminum foil crumpled up removes rust.
They mention some kind of product named McGuires for waxiing chrome.
Stuck stems and seatposts can be a bear. Lots of threads on this over at bikeforums. Lots of methods for removing them. Two basic factors are responsible for the problem: oxidation from the contact of aluminum next to the steel of the steerer tube plus rain and sweat that seeps in between those parts. Also, dried up grease from the last time it was serviced. Routine, yearly checking on the stem, cleaning and regreasing it is recommended to avoid the stuck stem problem, but many people don't do this...including me. Stems and seat posts getting stuck likely had a bit to do with why manufacturers came up with the idea for those ugly threadless stems that most bikes today have.
First, easiest prep for attempting to remove the stem is getting a can of PB Blaster...$5...Fred's has it. Figure out a way to spray the stuff between stem and inside of steerer tube. Takes anywhere from hours to days to weeks for it to penetrate and do the job. You'll have to figure out ways to apply leverage so as to twist the stem without screwing anything up. It's a challenge.
Other thing some have tried is a aerosol product called Freeze-Off. Auto parts stores have it. Idea is to spray it on the stem making it contract away from the inside of steerer tube just sufficiently to allow the stem to be twisted and broken free of whatever is holding it fast inside the steerer tube.
The shop is going to have to try all these things too...not really any special tools involved, so you might as well give it a shot yourself.
Worst case scenario is having to saw off the top of the stem, then making vertical cuts inside the stem to the inside of the steerer tube to break it free. People have had to resort to this method, but it's difficult and tricky.
I had a stuck stem in my trek 560. Nerve wracking experience. Went the PB Blaster route for 3 wks. Still had to turn the bike over to put the stem in a vise and twist the forks with a two by four between the fork blades...not the smartest idea...but I got lucky and didn't screw up the forks except for a very slight depression on the inside surfaces of the forks. Fortunately, the alignment didn't get messed up. Better probably, to somehow safely get the head of the forks in the vise and twist on the stem. Hopefully, your stem will come out much, much easier!
Unless you're really a purist, I wouldn't sweat taking off the old bar tape. At least on my SS, I thought the stuff was lousy. If you really want to preserve it for future use, take it off, put it in a box and store it. There's lots of nice tapes out there...cork, even leather (expensive). Both my bikes need it. I might do cork, but I'm hoping I can still order Benotto celo tape to top it off. Got a link to a source but haven't tried it yet. Not everyone liked Benotto, which came in bright, clear colors...smooth surface...stayed clean. It was a hit with racers for a short period. On the 560, I had it wrapped over a cushiony type of bar tape. Actually, still partly do!