This rig has no discernable manufacturer markings. Engine has not yet been inspected in detail for serial numbers and/or casting numbers, but it's clearly a Willys L-134, probably of 1944-45 vintage.
This had a half-track rear, the rear half is missing.
It has canvas fasteners around the windshield, and down the cowl, so it was intended for inclement weather operation.
Pictures all link to higher resolution images (640 x 480).