To get the buffalo into the truck take two 2X4's cut to the correct length and and drilled to accept a bolt on one end and make an A frame inside the truck. Use some 7/8 inch plywood as a ramps. Attach your com-a-long to the A frame and to the buffalo rear hoof (easier if he is dead). Winch him on up.
Well, the problem with the buffalo hunt in the Henry's is the top of the mountain is cold with snow on the ground and the bottom of the mountain is 90 degree heat. I was alone when I shot him and had to gut him out by myself. I got pinon branches and propped his chest cavity open overnight but even with the ground having snow in spots the body did not lose heat well. My friend came the next morning and we got him skinned and into the truck We just barely saved the part of the hide that was on the ground overnight and the meat near the front shoulder. You will see under him two tarps that we used to keep him from getting dirty as we winched him into the truck. I hate dirty meat.
Anybody who hunts buffalo alone needs to have a very good plan for dealing with a very big animal.