Speed-Lee markings

[Jc5]

OK, just to be clear: are you saying there is NO number at all on the top-rear flat part of the action where the bolt slides in (illustrated in my last post)? Is that correct?

It's becoming more difficult to investigate any further without more photos. Please try to post some more. I really want to solve the mystery of this rifle.

The knox form is the heavy part of the barrel where it screws into the action. Here are two illustrations to show the difference. The Magazine Lee Enfield (MLE, or "Long Lee") knox form (shown in the left photo) has a gentle "step down" contour. The Short Magazine Lee Enfield (SMLE) knox form (shown in the right photo) has a long, flat top surface.

Cheers!