TC1:

Beautiful rifle, and beautiful engraving.

I am assuming that the bottom metal is just the normal steel that is used for bottom in most Mauser and other rifles. Except for aluminum.

I have always wondered how what was put on engraved surfaces, when they were left bright, to prevent rust from forming.

Does your floorplate, trigger guard, quarter rib and other engrageved surfaces have any type of protective coating, or is is just bare metal?