Hi.
The Ministry of War (now MOD) placed an order for 12000 WM20's in the early forties. Contract No S5209. The unit cost was £68-10-0 ex factory.
This info was supplied by the RAF transport records when I was in the process of trying to fill in the history of my machine. Unfortunately very few individual records exist concerning actual machines in either of the forces. (realistically the same reply from Army and Navy)
I forgot I had this info.
Mike