Hi guys! restoring a vintage instrument to good/playable condition is interesting.
By the way, i have a question in mind. Here in our place i can see some students cleaning their old brass instruments with piece of small cloth damped with metal polish, making the brass shine well. Some say metal polish is applicable to use in brasses wherein the laquer/finish have been removed bec of old age, then to make it shine.
Why do teachers discourage the use of metal polish? Does it really affects the instrument ( aside fr making it thinner)??
Affects the tone, etc..??

In school, we were encouraged to clean and shine our horns. Perhaps the teachers that do not wish metal polishes to be used are concerned with safety and the effect they have on laquer. I really wouldn't understand why they would be against them. One would have to buff his arm off to do harm to the thickness of the metal with one of the polishing rags.