It's a nice example of a last ditch Japanese type 99. Considering the poor quality of metals used by the Japanese at the end of the war, I wouldn't try to fire it. Hate to destroy a rather collectable piece of history.
You can find parts at SARCO Inc or Numrich Gun Parts (e-gunparts). There's no telling if proper type 99 parts will fit in the simplified bolt. Might want to buy an entire bolt assy just in case.
Neca eos omnes. Deus suos agnoscet