Lavol. If you want to SPOIL your rifle by making it into a copy of an Enforcer - which it isn't and never will be, then go ahead and drill the body for the rings. But if you want a good, competitive telescope rifle that LOOKS like an enforcer but remains unchanged - UNLIKE a permanently changed Enforcer copy, then just put a steel one-piece scope rail onto it. Steady as a rock and available from Brian at BDLLtd in SC.
I know some with a less engineering bent/talent than me (if you'll excuse my pre-emptive strike chaps......) will tell you that drilling the radial breeching up/breech ring is a satisfactory way to go but in REAL engineering terms, it ain't and never will be. It's crap. And the Enforcer was ALWAYS the third best option that the then Home Office settled for because they were a) available, b) British, c) most cops were brought up on Enfields and d) cheap - because the government already owned them. They aren't my words, but the words of Major George Sxxxxxx who was running the Home Office advisory team at the time. The way to go is the BDL one piece solid-as-a- rock mount.
Just my 2c's worth before you start to drill, tap and eventually spoil a good rifle! I have my steel helmet at my side, awaiting the incoming from the Enforcer fiends...................