Took mine to an auto-electric shop. Rebuilds on starters, alternators, etc...
One day turn-around and that's with them having to order the regulator. $50 out the door.
Think your busted stud is off the voltage regulator.

 

I called NAPA and he said $200. Not cheap either. I can afford 2 hundred bones, it's just that this Rover won't see much action or ever be worth much. I'd gladly fix it for $50, however.

NAPA - 200
AutoZone - 191
PepBoys - 191
Oreillys - 191
AdvancedAuto/CarQuest - 251

Thanks. I epoxy'd the post on and checked the continuity once it dried. Perfect. It's probably stronger than the original. That was an easy fix. I re-mounted this old alternator and tested it to find the same .44amp draw as expected. Now that I'm up and running again, it buys me more time to fix this. I'm not in a rush now.

I've never seen an alternator/starter rebuild shop around here but I'll look again. If it's 50 miles away, that can be a 2-hour drive each way.

 

You can try and contact Paul or Will in my signature, they sell hand picked best of the litter. It's not a bad idea to at least ask them because your driving a vehicle that parts are either not readily available or are as you found out - mondo expensive. The alternator you have now is not OEM, it's aftermarket. Disco's came with Magneti Marelli juice whizzers, mine lasted until the truck was parted at 210k. Part # AMR2938 - 120A

 

Thanks.