I'll start by saying that I could be wrong, but I'm going to say it looks 1960s-vintage to me.
As for coachbuilder, I don't know, but that back door looks Superior-like to me, and the landau bars look S&S-like to me. If memory serves, I seem to remember reading somewhere that the Hollywood Forever Cemetery had Rolls Royce hearses at one time. I think that would explain the American-style landau on a foreign chassis, as well as the monuments in the background don't look like a European cemetery to me.