My brother-in-law spent 15 years restoring a '58 Corvette to Smithsonian-like perfection. The things were death-traps. Poor quality brakes, lousy steering. He added 4 way discbrakes and power steering. It's wonderful to drive and show off. It's not museum quality anymore buts it's driveable.
I have a 1940 Bates frameset. The frame is beat. It has ever so delicately bent seat stays.It'd take a while and a sum to make it Museum material, can't afford it, won't make the effort. It'll have an SA FM, B/W front, Stronglight Comp Chainwheel, Brooks. It'll ride like a Bates, AND, it's going to be ridden, BUT I'm putting Nitto Tech Deluxe and either Noodles or 115's on it so I'll enjoy it. Some bikes are restorable and need to be restored, some are restorable and shouldn't be touched. Some need to be resprayed, transfers applied, and then ridden with whatever parts you can put on them. Craig Montgomery in Poolesville, MD for a couple more days. riding a 68 inch fixed 81 HOldsworth with modern stuff onit.