I bought an 83 300D with 222K miles at an auction. It needed A LOT of repair to get it road worthy. The mechanic that I had work on it replaced the front sway bar, rebuilt all the calipers and installed new rotors and pads, installed new shocks, adjusted the fuel pump, changed all the engine filters and oil, changed the trans fluid, flushed the coolant system and installed new coolant.
He is very good and has a shop up in Lake Orion right off I-75 near the Great Lakes Crossing mall. His name is Peter Skrna and I highly recommend him. His number is 248-789-8606. He is also good at finding used parts for these cars.