To be more exact I would guess 1950-1970 but others know maybe better.
Steel wool with WD40 for the blade will work good. The brass cover of the scabbard will have had once a very thin silver wash so I don't know how to clean it best, every cleaning will remove more of the silver wash.
The handle can be cleaned with a damp cloth and a little bit soap but I don't see any dirt at the handle.
