OK...Those I saw for sale years ago through surplus dealers and went to collectors. I thought perhaps they had been deactivated like that...
As for the nightmare of the bushing replacements Peter...your thing thankfully. We kept the rebound socket in shape by foot powder and buffer washers but the rest was beyond our scope. Just clean and dry the telescoping parts.
Mostly on mechanized thankfully. The footborn times were few. You guys in the Falklands would have had a hard hump with those.
Our sight unit was the exact same sight.
Our trucks came back from the US with 40 oz bottles in the empty ammo boxes. The ammo liners kept them safe.