I don't know if this is the right place for this question, but does anyone have good images for the skinparts "menu-osu.png" and "menu-snow.png"? I wasn't able to find any via google.
no. menu-osu.png changes the osu sign that you see when buffering while spectating, for example. The standard-version is the pink osu! logo. The skin you can download on reimu's stream includes this: https://imgur-archive.ppy.sh/xtwhksl.png