I picked up a 1946 Mk IV back in the 90s for $100 and 1000 rounds of .303 British for $108. Never had a misfire from the ammo and it was all made in 1918. It is a war stick!
First one I picked out did blow up in my face though. The receiver had been hacksawed into, putting the lie to the claim by the purveyor that they were all bench fired prior to sale! I had checked it well, but had not disassembled the wood.