The Japanese started making 99's around 1938 or so. Several arsenals on the Japanese archapeligo plus Jinsen in Korea made them. Many different variations, more than 30 actually.
Having the mum is a plus. Not being sporterized is a major plus. It is hard setting a value on them as some folks think they're all crap and others don't. The earlier, the better as finishing was better. Some people flip over last ditch weapons. Your local enconomy pretty much sets the price, but I would value them at $150 plus.
Norma makes good ammo and any reloader can turn brass out of 3006 for the Arisaka.
<font color=red>Hate clouds the mind. It is better to have no emotion when it is work. Do what needs to be done, and do it coolly</font><p><font color=blue>A man who shoots when you don't call out doesn't have too many friends, but his enemies are surely all dead.</font>