We had 3 versions including a skeletonised version that the National Physics Laboratory had used to ascertain the requirement for bleed facility. The butt was an early Sterling SMG folding butt assembly.

I can tell you before you start that some of the stuff pumped out about the quietness of them is, how do we say it.......... 'somewhat flawed'. A silenced Mk2S Sten gun was quieter, as was the L34 using our very basic sound/noise meter. I say basic but Dr Phil Dater, who knows a bit about silencing weapons went over our figures and said that while the actual testing wasn't scientific as defined, say, under laboratory conditions, it was good.

There wiull always be slight dimensional differences during small scale production but Sterling and Ford were only a mile apart and shared toolmaking facilities. There's a bit more info in the Sterling book