But the top one in the photos doesn't seem to have the standard locking mech to lock it to the quite substantial bracket we see on the turret. It has a U shaped yoke and it was substantial too - as would be the recoil! The welding looks a bit rough too. Not like those Stokes we had and gave away. Last time I was at the Tank Mus. I see that they'd fitted them to a couple of needy vehicles. I think that they were bomb throwers as opposed to smoke. Can someone enlighten us?