Might it not be a sold out of service stamp not Q G.

A while back I blew up a pic of that mess and one by one whited out all the sold out of service arrows and x's, what gets left over is very close to QG, some of the letters are damaged by the marks but they can be seen. There's some other odd marks too but I'll have to have another go at cleaning it up to get them clear.

*1918 * barred out would only have the cut off replaced never had the windage sight on or replaced.
Thats why I began with that I added the cut off and windage sight, if no1mk3* refers to not using the cut off (?) then surely striking it out would mean the opposite?

lol, the odd feature of the serial number is the string of 8's, I've never seen an enfield with all repeated numbers, ever. I should sell it to some chinese man who thinks 8's are lucky.

Thanks for the comments ...