Hi Kevin,
Congrats on what looks like a very nice 250SL! I live in Mill Valley and my 1971 280SL is about completed after a very long, comprehensive mechanical and cosmetic restoration. I acquired my uncle's 1964 Porsche 356C Coupe from him last year and sent the car to Billy McNair @ European Performance in Novato. The car had sat in my uncle's garage for the past 10 years - Billy had to go thru the fuel system, brakes, etc. to get it running. He is super knowledgeable of air cooled Porsches and also works on old Mercedes. He's a 1 person shop these days so you need be patient but the result will be worth it. He's a super fair and honest mechanic. I'm planning to take my 280SL to him when the car is finished in about 2 months. Let me know how it goes and if you come across any other MBZ mechanics in Marin that come recommended.
Cheers,
Nate