There were two if not three Sherman BARVs on the Plain, all ex-Pounds. They were placed in exchange for more interesting targets..... There is one Centaur Dozer in the pics that was a swap for the Cromwell that went to Budge. The Cromwell in the pics is actually a Centaur, there were only two Cromwells on the Plain that I know of, at least on Larkhill side.
I spent many hours on the Plain recovering parts for various projects in the past. We considered nowhere to be out of bounds and I drove and walked all over the place. The impact area was often too rough and wet to take a wheeled vehicle and I certainly got stuck more than once.
There was a lot of blinds laying around, everything from 2 pr solid shot up to 155mm and aerial bombs, usually practice but not always. I never touched anything doubtful....
I never did here of any instances of people being hurt by things going off when tampered with, several rumours but nothing confirmed. You would have to be stupid to try though...
Acces to all ranges now is very difficult, we always went on with official permission, almost impossible to get now. :-(
Comparing the pics to mine, going back to the 1980's, it's certainly changed. It was all Centaurs, Shermans Rams, the odd modern target like a Conqueror or Cent, certainly no Chietains. Then there was the Tiger 1 track I found.....