Years ago farmers rigged up a semi-retired F-20 with a saw up front for cutting firewood - belt powered off the tractor's pulley. Maybe that odd front framing is the remains of such an enterprise.
It is an F-20 or F-30. Engine, tranny, rear drive are wrong for the F-12/F-14. F-12/14 had straight axles with inside bull gears like C, H, & M. The pics show drop axles & outside bull gears.