I couldn’t see much help in channels.
I went with the lightness channel in lab color.
Used multiply to try to bring back some detail.
I expanded the frame and gave it a light brown tint.
For the background I found noise and gradient looked too new.
So I tried to make a battered old background
that would look as old as the frame and Cadet.
Then came a lot of work cloning and using the Patch Tool.
Also used the dodge and burn tools to fill and even patchy areas.
Tried hard to keep everything looking old and worn.