They did, though although they were Holmes style, I think they were built by Reynolds-Boughton. There is at least one in preservation, but I haven't seen it for a long time. I must admit I've always wanted one, but never seen one for sale.
Yes, Richard did comment it was a civvy cab. That's what made me wonder whether it was Home Office, MoS or similar rather than military. Of course, that assumes it's the original cab.
The RS tippers ran 9.00 x 20 twins.
Yes, sorry Tony, I wasn't clear - I was meaning that other trucks or this timber tractor may have been converted later, not the one you were talking about.