(To add to that, for anyone looking for engine oil for their Bedford RL - just rooted out the workshop manual for mine and it seems that post-1955, the engine oil is OMD-330 - which would translate [if I understand all this correctly, which is always open to question...] to a 20W50 such as the various 'classic' oils about. Checking in the yahoo RL group seems to confirm this. I'm guessing that your notes, Clive, are for earlier models...
Thanks again - learning all the time about this amazing behemoth of a vehicle...)