Old African knives

[Pieje]

I only speak about cleaning/preserving the metal, which is not the same as altering a weapon by sharpening its edge or colouring feathers.
Cleaning would reveal details of the forging process, beautiful patterns or copper decorations/inlay.
Daily use would keep the weapons in good condition. If stored or unused for a long time, they get dirty and rusty. Rust is not a patina.

I’ll add as an example some pictures of a nice sword from South Congo. The first picture is when I bought it. When cleaning I’ve found a nice surprise in the form of a great and unusual decoration (figure and flower) and 2 tribal repairs, a brass and lead inlay probably to fill up gaps that occurred while forging the blade.