Jeff, it's a 1945 7B3 model FAT, and a Ford, not a Chev. The Argentinians and Portuguese seemed to acquire most if not all of these under post-war aid. It was the ultimate Canadian development of the type, superceding the beetleback design and was similar to the late production Morris FATs.
Here's a pic of another one owned by Manuel Vasquez in Argentina.
http://www.oldcmp.net/Images/fgt/vasquez/Vasq_08.jpg
Lots more pics
here.