I wouldn't buy it. Not because of the price or condition. Notice how the loader control is 2 levers? That reason alone i would walk away. I am sure it is something one would gets use to. For me loader control lever location was a must for me. Needed to be single lever and located near drivers station. I also wouldn't buy a unit with the control valve located on the loader. Have fun with your search.
I just bought an 855 with the 70A JD loader in similar condition for 8700. I found several 855-955 with loaders for 9 grand. I agree the brush hog looks way to big on that tractor. I wonder if it was actually used that way or they stuck it on to make a package. I wouldn't pay that for a gear tractor with an aftermarket FEL.