Larry, I don't know if you mean that you have never seen a CMP truck like this used as an ambulance or used as an ambulance by DAK, but here is a photo of a C60L used as an ambulance.
It says 30 cwt, but I think it is a 3 ton, the tyres looks like 20 inch...
Rolf
http://img496.imageshack.us/img496/7530/e0095430gw.jpg
Description: THE BRITISH ARMY IN NORTH AFRICA 1942
A Chevrolet 30cwt truck in use as an ambulance with red crosses painted on its canvas tilt, 22 March 1942.
Source:
http://www.iwmcollections.org.uk/dbt...&BG=0&FG=0&QS=