Post (or PM me) the serial # of the tractor. It's on a small plate below the dash, right in front of the shifters. With that, we can determine the year (and approx month) of manufacture.
I see why the 3-point hitch doesn't work. A relatively simple fix that will ALMOST take care of itself when you remove the loader. The point where the hydraulics are attached to the rear end housing (under the seat) should have an isolator valve (loader OR 3-point) or, once the loader is removed, a plate that blacks off the hydraulic ports going to the loader. An isolator valve allows the flow going to the loader circuit to be shut off, directing flow to the hitch. The "blank plates" appear on ebay quite frequently. If you need, I can furnish you with a Massey Ferguson part # for the plate. (If possible, post a close up of the point where the hydraulic lines attach to the rear end....That MAY be an isolator valve.)
Does the MultiPower work?
Things to check. Look under the transmission and bellhousing. THere should be 2 weep holes. There should be cotter pins sticking through them. (They keep the holes from clogging with dirt) Is there any oil showing at these holes? Significant amounts? Transmission oil or engine oil? If tranny oil, look to replace input shaft seal OR MultiPower seals. Engine oil? 99 times in 100, rear gaskets on the oil pan. VERY rarely the rear main seal.
If you have ANY electrical issues, (gauges, charging, ect) replace the oil pressure switch attached to the oil pressure gauge. It detects oil pressure upon start-up, switching on power to most of the electrical components. Any electrical issues are almost impossible to correct if this switch is being "difficult". It's available through TISCO as well as MF/AGCO. I can't count the number of times I've seen people trying to diagnose and repair elect. troubles where this switch was causing the problems.
Since this tractor has had a loader, good chance you'll need to look at the front axle pivot point. It has a replaceable bushing. It tends to wear (excessively) with loader use. When worn, it will cause a very sloppy steering and handling.
Get a service manual and parts manual to go with the owners manual. You'll be WAY ahead of the curve. Parts manual is valuable even without part #'s. It shows exploded views of sub-assemblies. Owners manual is very limited and vague. You NEED the service manual.
Contact BIG DEAN AUSTIN.
http://hometown.aol.com/bigdean62/index.html Get his CD on service and repairs to the 100 series MF's. It's the single greatest piece of information you'll get on these tractors.