Thunderbird wins: it's my No1MKV (not Mk5, Peter ... but you knew that, of course). And well spotted, Gunner, for detecting a piece of well-disguised me.
Being too impatient to make a proper setup, I had the rifle rested on my shoulder and shot myself with the camera throught the back end... I hope that's reasonably clear.The clues were 1) It's an Enfield, as you can see from the system with the bolt removed 2) you can just about see the cut-off plate 3) you can also see some kind of a backsight behind the charger bridge (exactly what kind will be revealed later, if I have the nerve to photograph it.
Anyway, the next pictures show why I bought it, in spite of the dreadful external appearance. The first photo shows not the rifling, but the rifling reflected in the absolutely mirror-like chamber, and the second shows the rifling itself. Notwithstanding any possible comments from Peter about being made on a Friday afternoon when the tea had run out, I reckon that was an as-new barrel. The rifle still had fossilized cosmolene below the waterline, but the external appearance... oh dear!
Patrick