Those Stevens actions are cast and usually turn purple after a while when hot blued.

If they'd take an eraser to the critters on the sides, they'd probably find them to be silver inlays.

A broken top tang is a frequent problem on those and they don't weld easily even with whats available now. I think they might have spliced a new top tang piece on for a repair somehow after squareing up the break. Looks like it has separated again.

They do silver solder quite well but it shows when it's blued, and it won't take the heat of C/C.
Braze will make it through C/C but will still show a line.

Alot of work in that Stevens.