You can make this a bit easier on yourself by picking up the driver's rear door lock motor and a passenger's front door lock motor and linkage. This will give you factory parts that will bolt in, at least. The "custom fit" actuators require you to hack up your door skin- these bolt in in the correct location.
Jo-Di's does do a great job with these, but as you say, they get top dollar for it. You will need the control box from a keyless kit to make this work.
Basically you make the lock motor that you add operate the driver's door lock rod- the rest operate just as if you pushed the button down yourself. Only the driver's door has no lock motor, do that's why you have to connect this linkage. You'll need to run a power wiring harness to the new motor- try to grab one from one of the lock motors you get in the junkyard.
If you can't find a donor car, try Autowerkes in New London (860-443-1066) or European Auto in East Lyme (don't have # handy). They both have plenty 'o parts cars.
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total