Service the bearings and leave it the hell alone. It is a survivor and repainting it really isn't going to make it worth more and in fact it may make it worth less. I personally like old bikes that show they have been enjoyed for a LONG time. If you want to single speed it go find a set of alloy wheels and go for it but put the original rims some where safe where they wont rust out. Anything you take off save and DO NOT CUT OFF ANYTHING!
Around here unless it is rusting I tend to get my best prices on original frames. People were killing themselves to get the 70ish Raleigh Grand Prix I had because it was still in original paint with original decals and B: it had all its original bits with it in a bag. Rode really nice and sort of wish I kept it but I have way to many bikes right now.