Here is what I learned about this gun
Early to mid 1940's mfg from the Nagoya Arsenal, Type 99, 7.7 mm Jap, the mum has been ground off.

Someone sporterized sometime in the 1950s or 1960s, they shortened and recrowned the barrel to 23", shortened the tangs, bent the bolt handle and modified the bolt using M1903 Springfield parts. They then added custom sights (Lyman Peep rear sight, ramp front) with a walnut Monte Carlo stock