Over the years there have been a number of cheap "commemorative" or fancy pistols made where brass plating was used as a cosmetic enhancement instead of more expensive gold plating.
It looks OK, and is reasonably durable if applied in a heavy enough coat.
It does tarnish, being just brass, and you have to be careful about using any kind of polish, since this quickly wears through the plating.
Also, like all cosmetic platings, the metal can and will rust UNDERNEATH the plated finish, and you first hint of trouble is when rust appears on the surface.
