I watched a few videos he has done. He done Traditional rust,
hot caustic,
copper conversion

and a few variations.

https://youtu.be/zHDc9YjPTLI

Looks like he is saving history one gun at a time. That certainly is a vast improvement. I'm sure the purists on the collector forums would have a fit and say the rust was just a part of its history, and that you should just oil it.

Thanks for posting Rich.