Awesome car, I too am jealous! I agree with the advice already posted about your alternator. My method of troubleshooting would be;
#1 - swap in a known good alternator or have yours tested
#2 - replace voltage reg with a kn own good, or quality new one
#3 - bulkhead connector - you should inspect and clean this regardless
Good luck with it.....if you want your money back out of it just let any one of us know, LOL