Try:

http://www.mbzbest.com/

I know it's a fer piece from your location, but I hear they're good, and above all, honest.

I've sent my son-in-law there, and he seems reasonably happy.
They're not cheap, but charge a lot less than the dealership nearby in Torrance.

We had a one year old '74 SLC back when we lived in Westlake Village.
She got it of course in the divorce. She could well afford it being in RE.
I kept my 240 Diesel.

They'll nickle and dime you ($500 and $1000) to death if you don't find a good mechanic.

I found ours ran best at 8 degrees advanced instead of the retarded whatever was
recommended by the factory. 'Course, yours' being a '76 may be a little different?

Good luck with that beauty.