[David_Hayward (RIP)]

Hello again! If you mean 4 x 2 Modified Conventional Pattern trucks, as against 4 x 4 CMPs, C30S and C30, then here is a partial answer as the official GM of Canada civilian rating was 2-tons. There is a famous photo of a line-up of 1940 Model ambulances, built on what must have been 2-ton Model 1543 chassis and cab with 158.5" wheelbases. The reason I mention these '2-tonners' in reply to your request about '30-cwt' trucks is that in the US they were rated at 1.5 ton. Then for 1941-2 we know of 1-ton 1421 chassis with flat-faced cowl which could have been 30-cwt military rating. Then there were 2-ton Model 1533 2-ton 134.5 " wheelbase. Also there were the 1941-2 Model 1543 which were 2-ton civilian rating but 3-ton military, with thr 160" wheelbases.

GM of Canada also supplied both Maple Leaf heavy trucks as well as GMCs in the 3-ton range.

I also know of a 1945 Model 1543 that was delivered to the UK. This may have been a '2-tonner' by then or 3-ton military rating.