Most old guns are not worth redoing. Leave them alone and accept their scars and dings as badges of honor. That said, you may own guns that have a sentimental value and wish to improve their appearance. Such work does not increase the gun's worth to a collector, but nonetheless enhances the owning experience to you. If that's the case, go right ahead. In 1972, my uncle left me a sadly neglected 1930s Pigeon Grade Browning Superposed. I had the barrels reblued, the stock refinished, the checkering recut, and the recoil pad replaced because it was a fine old gun and I couldn't leave it looking like hell. I might have cost myself some money by diminishing its value to a collector, but I couldn't care less.