Thanks Richard, I've googled Bedford RL and the compressor doesn't look like mine, not that I'd have minded but it makes it that little bit more special knowing it came off a heavy Scammell.
FYI, mine has a solid 2 belt pulley fitted, no holes like the one in Andy's photo, that doesn't necessarily mean it's always been there?
Andy... Does your parts book list a number for the complete pump unit? I've found a website that deciphers VAOS parts numbers, this tells me that the [P3960] is a manufacturers part number, I've had no luck finding a gasket using that number.
Thanks again.
Max