From the description: "Our 280SL has spent all of its life in California as the data card indicates that it was manufactured to an American specification where it was sourced."
Apart from that I don't understand the "where it was sourced" bit, I am always suspicious when a seller claims that a car was "always in California". Unless the entire paper trail is there, the car may have been taken to California just a short time before sale, so the previous seller could claim "California car".
They also say the car had its original rust-free frame rails, yet they plan to replace one of them which must be a heap of work to do. Perhaps it was a bent frame rail, or it wasn't really rust free?
Maybe this is a very reputable and high quality shop, but from what I read I am not yet impressed.