From what I have researched they used Japanese Walnut, Japanese Beech or Katsura depending on manufacturer and/or year. I have a fondness for bayonets and daggers and looked at my notes on the Arisaka 30 bayonets and can't remember where I got that information. Pictures of various type 30's seem to show all three.
If you aren't trying to restore it to accurate military specs for sale to a collector or whatever I think the walnut grips were the best looking.
From what my notes say they stopped using the hooked quillon around 1942 so if it has one it might be worth more than you think.....maybe.
Research on the maker might provide more information but as I only collect bayonets for the Mausers I have, I have not done in depth research on the Japenese bayonets yet. I've thought about procuring a Arisaka Type 99 rifle from time to time. Your bayonet would fit it.
Hope this helps.........