I vote that you clean it as well as can be, oil it, hang it.
Trying to re-blue or paint the metal will create an ugly stick.
While your at it remove the firing pin and toss it. Depending on when it was built the "quality of build" was spotty right out of the factory. Add some rust in the chamber and/or bolt, and it might go BOOM if someone was to find some ammo.
Additionally, Check to see if the chrysanthemum is on the receiver top. There could be some collector value. Under the flower is the type.
http://www.castle-thunder.com/model.htm
Net Net: The less you do the better, clean & oil..