James,
Sounds like a great modelling subject. See some older thread s on here which may help you on your way. The Italeri CGT 1:35 scale model may be a good start. Even if it is a Chevrolet and has the Canadian body, at least it will give you parts and dimensions to do some kit bashing.
CMP #9 gun tractor model-build log
cgt model info
1/35 scale Chevrolet C60L by Italeri
HTH,
Hanno