WW 2/Korean War era rifle id help

My 80 year old mother is selling her house and having an estate sale to get rid of a ton of stuff.

The one thing the estate sale people will not sell are firearms, and she has a rifle that my late father was given by a friend who served in Korea (dad was in the Army at that time, but stationed in Germany).

It has been a while since I have seen the gun, so I am going off memory right now. The rifle is a bolt action, with detachable bayonet. I do not think it has a place for a clip to be inserted at the bottom, but there is a spring loaded door at the bottom of the breach where rounds can be fed. The only markings on it are in Japanese/Chinese characters. I'm not sure if it is Chinese made and was used by the Chinese/Norks in the war, or if it is Japanese made and was left over from WW2/occupation of Korea.

Does anyone know of a definitive way to tell, or the type of place I could take it to have it authenticated? Once identified, how would one go about selling something like that?

tl;dr - Looking to identify 60+ year old east Asian bolt action rifle.