Occurrence of Verdigris and other patinas in the common hoplite panoply.

[Sean Manning]

I agree, and also, gentle polishing is not that damaging.  You don't need aggressive cleaners or hard sand, just a rag and maybe some dust.  The important thing is that you clean it every time you use it, and store it somewhere safe from water and debris.

People who try to shellack metal tools such as armour find it is a disaster, because the coating yellows and because eventually decay starts underneath and the only solution is to strip it off.  People obviously have more success with waxes, oils, and other fluid coatings on steel but I don't know of evidence for waxing bronze in antiquity.

In later periods, ferrous plate armour only had a working life of a generation or two anyways.  Eventually it would be too old-fashioned or too worn and get remade into something else or put away as a curiosity.

Really, the best thing is to buy something from Neil Burridge, put it up on a high shelf and watch what happens to it!  As long as you don't make a bunch of thumbprints then ignore them, I think you will find that it needs less maintenance than you think.