Thanks Ron. That's interesting and I'll certainly have a look at milsurps.com. I know there were different versions of that band for the No4 (forged vs stamped etc), I still wonder why they would have decided to make ones of significantly different size and shape for the No5.
This being said, even if only talking about the band for the No4, shape and size can vary (that's what I find anyways when looking at many bands I have here, and that I've had in the past). Add to that the fact that, between two No4 rifles, the exact depth of the groove in which the band goes varies. So final fitting, I guess, always has to be adjusted... Which is part of the charm of the Lee Enfields!