Sounds like a bargin for a 4x4 tractor.
You might do a compression check, or have it looked over at a local tractor dealer. If it runs and 4x4 works I really don't see how you could go wrong.
Here is some info on it from tractordata.
http://www.tractordata.com/farm-tractors/000/2/4/245-ford-1100.html
1979 - 1982 Hundred Compact Series
Compact Utility tractor
Next model: Ford 1110
Larger: Ford 1200
Overview
Engine
Transmission
Dimensions
Photos
Attachments
Production:
Distributor: Ford
Manufacturer: Shibaura
Factory: Japan
Original price (USD): $5,609 (1982)
Ford 1100 Engine:
Shibaura 0.7L 2-cyl diesel
full engine details ...
Capacity:
Fuel: 3.5 gal [13.2 L]
Hydraulic system: 5 gal [18.9 L]
3-Point Hitch:
Rear Type: I
Rear lift (at ends): 881 lbs [399 kg]
Power Take-off (PTO):
Rear PTO: transmission
Rear RPMs: 540
Front PTO: optional
Dimensions & Tires:
Wheelbase: 48 inches [121 cm]
Weight: 1,131 lbs [513 kg]
Front tire: 4.00-12
Rear tire: 7.00-16
full dimensions and tires ...
Ford 1100 attachments:
mowing deck
snowblower
front-end loader
backhoe
all 1100 attachments ...
1100 Serial Numbers:
Location: Above front axle on left side
1979: U125001
1980: U127591
1981: U129066
1982: U130665
1983: U131359
how to read serial numbers...
Ford 1100 Power:
Engine (gross): 13 hp [9.7 kW]
Engine: 12.5 hp [9.3 kW]
PTO (claimed): 11 hp [8.2 kW]
Mechanical:
Chassis: 4x2 2WD
4x4 MFWD 4WD (optional)
Steering: manual
Brakes: differential mechanical drum
Cab: Two-post ROPS.
Hydraulics:
Type: live
Capacity: 5 gal [18.9 L]
Electrical:
Ground: negative
Charging system: alternator
Charging amps: 20
Battery:
Number: 1
Volts: 12
Amp-hours: 72