If you want a Type 30 to shoot, my advice would be to find a Type 30 you can shoot. They are out there and not unreasonably expensive. In many cases, the seller has no idea what it is and to them it's just an Arisakaicon and they price it accordingly which is lower than what a Type 30 normally goes for.

To do what you propose would be to create a frankenrifle that has no value to another collector or shooter for that matter. Training rifles are collectible in their own right. But if you don't appreciated them for what they are, their parts can also be sold to fix existing Type 30's.

I've been trying to find a stock for one for several years.