Welcome! This is a common situation, and most people either:
1. fit repro pads and bracket, and make a replica. Fultons have these [at least, they did recently] and if you carefully read the threads on how to do it, it sounds like you have the skills to make a success of it. The overall value of a No 4(T) replica is roughly the same as the parts added together. So you wouldn't erode your investment; whereas tapping a top rail into the receiver would permanently take £££ off the value of your rifle.
2. go down the "no gunsmithing" mount, and if you choose this route, the £140 mount from Fulton's is highly regarded: Fultons of Bisley - FULTONS NO GUNSMITHING SCOPE RAILS FOR Enfield Rifles SR2
If you find the scope is too high, you could fit a £24 repro cheek piece from DS Solutions Search - cheek
Finally, before you 'scope your rifle, ask yourself whether the rifle shoots excellent groups, in the hands of a good shot? If it doesn't, then I suggest don't 'scope it. Many people think a 'scope will make the rifle more accurate. It doesn't - it just makes the target look bigger. The market is full of unsold 'scoped rifles, esp. Mosin Nagants and K98s, which simply can't group.
Rob