Here is a list of dealerships from this thread.
https://forums.pelicanparts.com/porsche-marketplace-discussion/1008654-what-porsche-dealerships-were-so-cal-1973-a.html
1) Beverly Porsche+AUDI, Beverly Hills
2) Bob Smith PA, Hollywood
3) Bozzani P+A, Monrovia
4) Catron P+A, Pomona
5) Chick Iverson P+A, Newport Beach
6) Circle P+A, Long Beach
7) Don Burns Prestige P+A, Garden Grove
8) Gabriel&Olsen P+A, Encino
9) Green Motors P+A, Norwalk
10) Kendon P+A, Wilmington
11) Ogner P+A, Canoga Park
12) Porsche AUDI of Downtown, Los Angeles
13) Ralph Cutright P+A, Santa Monica
14) Rusnak P+A, Pasadena
15) Sierra P+A, Riverside
16) Vasek Polak, Hermosa Beach
17) Victoria Motors, Victorville
18) Westwood P+A, Los Angeles
I remember there was also one in Glendale. It may have been called Glendale Porsche or Allred Porsche.