Can you get the serial number of the tractor. Just dawned on me that they only made the the 800 in 58 and 59. The 58 had a rotary style injector pump while the 59 had inline pump.
Not to bad mouth the 800 but I have seen several 800's with loaders that the brace bar of the loader was bolted to the engine frame and it actually busted the block and ruined the engine. I know lots of people put loaders on them but be careful.
I have been around the 3010/3020's and the 4010/4020 tractors. I used to own a 4020 with a 148 loader and it was a very good alround tractor. Actually was bigger than what I needed, just right for farming but little big for my loader needs. Liked the deeres forward / reverse on sycro. transmission.
Another option maybe the Case 70 series tractors. I'm not to familuar with them but haven't heard anything bad. I just feel the 800 isn't the way to go for the money. Also with out seeing the set up it's tough to infor someone which way to go. Got pros and cons both ways.