So, maybe I got it done. Maybe….
I took the voltage regulator/brushes out of the 89 Towncar alternator, and from the number, it was 65A, remanufactured. The rotor, where the brushes rub, looked almost like new.
I pulled the voltage regulator/brush assembly out of the Missing Linc without taking the alternator out. I couldn’t see anything wrong with it or the brushes, but…
When I took the flashlight and I looked inside, there was a little piece of trash between where the brush runs on the rotor and the Aluminum housing of the alternator. That track was closer to the opening, and was grooved out maybe 1/32 of an inch. So I pulled the whole alternator out. I had to take the wire with it, which ran across the top of the engine all the way over by the firewall, no plug at the alternator.
The brushes from the Ranger were worn down, but from my memory, not completely worn out. The one running in the groove where the trash had cut the rotor was shorter than the other one. Of course, I got the piece of trash out. Other than cutting the little groove, the rotor didn’t look bad. The brushes from the 89 Towncar alternator were a little longer, but I still think they were at least half gone.
The 89 bottom connector was the kind that had too heavy black wires, and one thin white wire. The Ranger just had two big black wires. My gut tells me they’re interchangeable if I could figure out where that white wire goes, but I decided to proceed with the Ranger original.
I went poking around in the shed of miracles, looking for a set of brushes, and I couldn’t find anything that would work, but I found a bad alternator I saved from my 1997 caravel 21’ bow rider I/O runabout. I sold the boat 15 or 20 years ago, so I decided to throw caution and reason to the wind, and risk it, and take that bad alternator apart. Turned out it had pretty good brushes, half again longer. I used the soldering iron to take them out. Just by hand, I rubbed them back-and-forth on a piece of 100 grit sandpaper a few times, and they fit perfectly.
I crimped on couple of eyes on those brushes and put the whole thing back together and put it in the Ranger. So basically, I have the same alternator, a little groove cutting the rotor, but almost brand new brushes. Sitting in the driveway and turning on and off the lights, the highbeams, the heater blower, etc., it seemed to be working fine, running at a higher place on the gauge than it was when I was driving around yesterday.
No test drive yet, but that’ll happen before the end of the day, and I did put a full charge on the battery overnight

Thanks again