So here is an example that I found on Gunbroker, to help me gauge how much do rifles like this one go for.

WWII JAPANESE T99 ARISAKA RIFLE W/ MUM-1ST SERIES - Curios Relics at GunBroker.com : 796981244

Good condition WWII Japanese Type 99 Arisakaicon rifle in 7.7mm caliber that has a full untouched mum on the receiver and was manufactured as part of the 1st Series by Nagoya Arsenal. Rifle is NOT import marked and has nonmatching numbers. Metal finish is original blue with some turning brown and some light pitting throughout. Bore is about very good, mostly bright with strong rifling and a few dark areas. Stock has added varnish and shows some normal handling marks. Rifle is complete with correct original cleaning rod, anti-aircraft wings, and monopod