Sorry to paraphrase you but I wanted to cut to the chase. And I would like to say these are only my personal views, you can do what you please with your bikes. A 0.125" ball bearing is a 0.125" ball bearing, replacing a worn one is imperceptible. But a Model 35 Universal brake is not a Model 39 Universal brake (assuming this bike is from 1935). If the original brake is working, there is no reason to replace it. But if it is broken, a period correct Model 35 replacement is, in my view, perfectly acceptable if you still want to use the bike. I would keep the broken brake though, it would never become landfill. A Model 39 was not available at the time and technically no better for the bike than some Zero Gravity brakes. Now, if you can get the Model 35 and you have some 39s to use, great, but I would still be working on getting some 35s.

But that's about very functional components, let's talk about finish. Other than inhibiting rust, paint, nickel, chrome and decals (they offer no rust protection) are purely cosmetic. With paint, ask any painter, if you are not using paint from the same lot, it will never match and you will cover the original aesthetic, it will be gone forever. Decals are similar in that unless you have some NOS versions, any replacements will never match. Replating nickel or chrome will destroy any original paint. Now if the majority of paint was missing, I would consider a repaint, but it would take me a long time to make that decision.

Now also consider how you will use the bike. If the bike has a high value to you, you will probably not use it as a winter beater or a commuter. Determining that personal value is subjective. This particular Gloria is objectively quite rare, there are probably very few left. For me, that raises it's subjective value. I am also drawn to bikes of that era. I wouldn't ride it often, only the occassional Sunday ride, never in salt or rain and certainly not in a race. With that kind of light riding, there is no reason to believe it wouldn't last another 70 years. So really there is no need to repaint or replate the frame or components when wax will protect any bare metal.

I also like the history the patena holds. I like looking at the chips in the paint and imagining the circumstances of how the chip happened. I have heard the arguement that if Fausto Coppi's sweat didn't cause the rust then it isn't worth keeping. I find the whole "only famous people make history" to be bunk. I find it much more interesting to know how everyday people led their lives than the famous. I can relate to the commoners much better.