Hi Tony
I started with ATZs and the almost identical tyre is now known as All Terrain Deegan 38. Deegan is/was an off-road racer who used MT tyres.
The Cruiser has ATZs on the front and 38s on the rear, all with similar mileage/wear of course, and the ATV has ATZs all round.
I have heard the claim about MTs and Coopers and it appears MT is one of the Cooper Tyre company's many brands.
Bas