Wait so this John Jovinco fellow, the name seems familiar, he brought a lot of Lithgowstuff to america right? Or did he also get it sent elsewhere? If it was on the sight bed I would be thinking that maybe it was a replacement part sourced from the US after he had imported it, but on the barrel? Seems a bit far fetched that the rifle served and then was sold, then JJCO imported it to the US, and then it came back here?
Also englishman, I'll have to check my Lee Enfield book for contractors that might have those initials, maybe check the rest of the rifle for 'JC' as well.