I recently came to the conclusion that the unknown 75mm I use as an avatar was fuzed with something akin to the MKVI Fuze as used on the U.S. Stokes Mortar. One of the members here kindly brought one from his collection to SLICS where I was able to try it with the round. After fitting the fuze loosely to the round, I found they were a perfect fit for size and thread pitch. Due to corrosion in the threads, I wasn't able to seat the fuze, but was able to confirm my premise. Any comments would be appreciated. 
