My WH M1 is with you now for some of your magic. A blued M1 bolt is with it, requested to be burnished to 'bright bolt' appearance. It sounds as though, metallurgically, this bolt will now be identical to the originally un-blued bright bolts, and will appear so to the eye. Is this a fair assessment?
My M1928A1 came with all of its original internals, and is in nearly unused condition. I obtained a Savage-made blued bolt to use for shooting. It was NOS, in the wrap. Soaking overnight in Lime Away removed the blued finish, and I burnished it to the best of my ability with a steel wire brush and steel wool, but it still does not have the almost aluminum-bright appearance of the original 'bright' bolt. With a light coat of oil, it appears gray. One would never confuse one bolt for the other! I am not trained in metellurgy, and it was this appearance that led me to believe that the later, blued bolts, were of a different steel composition. Sounds as though I was not able to deep clean the bolt, and some blue has remained, preventing the bolt from gleaming like its untouched original counterpart.