Gooday,
The Greens were made from around 1949 to the early 1950s. Price in 1949 was 36 pounds ($72) plus Tax. The full name of this one is the "Master Lightweight Motor Mower" and was advertised as being able to do a 1/4 acre block in an hour !!! The width of cut (to finally get around to answering your question), is 14". They made some 17" models in 1954, The engine in the commonly used Villiers 98cc.
Our museum was given two mowers from a deceased estate. I will get photos of the other mower that has a BSA engine on it (the one similar to the late Mk 10 Villiers), as it doesn't have any markings on it that I can see - and someone might know of it.
Stationary