The exterior door handles should be the same 1981-86. I think Alfetta and Montreal handles will swap out, but are chrome. If your problem is the paddle has snapped, I only have an extra for the passenger's side to offer. If you need some of the other bits to repair yours, I do have a collection of other D-side bits to offer.
On retaining the lock cylinder in swapping onto a different handle assy, I went thru that recently in repairing a unit where the lock had broken free of the assy. The cylinder is connected to the body with swaged studs from the bezel around the key hole. Seldom enough of the pot metal swaged head left to defeat and re-swage. So I drilled out the studs from the backside and counter-sunk a beveled recess on the front to allow a couple of small stainless screw heads to become flush. Then nuts on the screws, and Bondo and paint to hide my evil work. Racingswim offered an option that sounded easier. He said he had used JB Weld putty to 'glue' the lock cylinder back onto the 2 studs. Both options are likely stronger than the original factory method.
