Just reading this thread alone it would seem that there will never be the definitive book about Enforcers. How could there ever be?
I also have the most severe doubts that there was ever a shortage of Enforcer rifles. It's like saying that there was a shortage of No4 rifles! They were a Government contract via the Home Office to a specification and if the Government tell another Government factory to make XYZ, then they do! At the time Enfield were actively looking for commercial work and would sell barrels. Indeed, they were already selling the private venture Envoys commercially to anyone via a registered dealer!
As for the notion that Police Armourers could convert another rifle such as an Envoy to an Enforcer and THEN mill out the old markings and THEN re-engrave it and THEN............... I could go on. And where in heavens name would he get the a) wherewithall, b) accurate measuring facilities in order to achieve the accurate fitting of the mounts etc etc. Once again....., I could go on
We know that some - and I leave it at that - have actually drilled into the barrels to screw down the front scope mount. Not just drill into the barrel, but drill so far that the chamber has bulged!
Nope, I'm not sure that there will ever be a definitive book Al. A discussion papre maybe but............. And remember this Alan. When you write a book, the FIRST person to read it immediately knows more than you. That's because he already knows the tiny bit he knew before PLUS all, every last bit, of what you have just researched and written.