Maybe your problem isn't the charging side. Maybe it's the ground. I've had a few electrical problems that tested fine to the battery ground but zero to the frame. Corrosion is a great insulator. Did you switch out the alternator relay? That's the one that switches the circuit from crank mode to run mode. Blue cube in the relay box on mine. If that's kaput you won't get fuel. Maybe the fuse sockets are corroded. Pull them out and plug again.

As old as it is you have to assume all those years of rattling down the road might have loosened something. I recently had a problem with headlights that wouldn't come on. Relay just wouldn't pull in. After many hours of banging my head in the engine compartment I found the real problem was under the dash in the connector block that connects the interior wiring harness's to the exterior ones. Some electrical contact cleaner and plugging it in and out a few times solved it. Maybe the ignition switch connector is your problem. The relays work on such tiny amp levels that even a little resistance from corrosion or looseness is enough to stop it from working.