It's always sad to end up with a rifle that way. Still, it can also become an object attached to good memories.
For that purpose, I guess, the Lee Enfield is quite a great choice.
Markd, indeed some pictures would help; especially of the numbers and letters stamped here and there (usually right side of the action / barrel and the band where you noticed the "ShtLE"). My guess at this point is that the barrel, if it's the only one with the J216 number, and the receiver would have the V15378 number on it, the rifle would have had its barrel replaced ad some point? Which is not unheard of.
Mostly, though, as far as I am concerned, I would want to know if there's wood all the way up to the muzzle, or if the rifle has been "sporterized".
Cheers,
Lou