Look up "zero-mile" in the FAQ- these are ALL the things you would do to make your car as reliable as possible. An awful lot of the 700/900 series info applies to 240s as well.
For you, there are standard repairs items any car would need:
Brakes, Tires, Exhaust. Make 'em all new and don't worry about them for 40K miles or so.
Then the normal items you would want to go through putting this older car back on the road:
1) Belts + hoses, including timing belt and any split / missing vacuum lines.
2) Complete tune up including flame trap service
3) Front end wear parts, ball joints, inner + outer tie rods, struts, bushings
4) Cooling system complete service- radiator + waterpump if needed, pressure test system, flush fluids.
5) safety items: wiper blades, windshield washer, all lights working?
6) Address all oil leaks as time permits.
Good luck and have fun!
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE: 625K total