It sounds like you are referring to the B30 or WB30, there are several posts on here about them, try using the search box at the top of the forum, or better still buy a copy of Chris and Steve's book, British Forces Motorcycles.
Yes, That's it! Cheers. I Couldn't remember what it was called, and where I'd seen it. It would have been in the book British Forces. Thanks for the heads up on the posts in this forum. Searching now for a squizz.
Very nice looking bike! Might be a nice little 'replica' project. :)
Thanks again. - My brain is like a sieve these days.