In my opinion lifting the head is the least of your concerns. A chain hoist is around $90 at Tractor supply and a good investment anyway if you don't have one. The head can't be all that heavy as another guy said. HOWEVER, that better be one heck of a good price on the old MF135. We have no idea of your circumstances, what tasks you have to do, how much acerage you are working, what other equipment you have or attachments you already have, etc. Being a Continental means it is gasoline, right ? Any idea how many hours? Do you not need/want something that is 4WD ? Too many questions to recommend you much. What makes you think its "more tractor than you need?" We talkers out here are full of opinions but need more to go on to offer you much help.
p.s.: the old Continental 4cyl engines ran forever it seemed like. I have a 1954 MH Pacer with a continental 4cyl that runs fine, does not use oil and will run for 2 days on a 6 gal tank of gas. No idea how many hours , not high. But then the diesels run even longer (probably) and have some advantages in tractors with torque, etc.