WW1 'Periscope Prism company' sniper scope???

[Roger Payne]

Many thanks; for a rather dry subject you have put it very well indeed! As you say, sometimes a picture helps. The M prefix serialled scope? Yes, I suspect it is likely indicative of a rifle taken from available stores. I know that most surviving examples of WW1 SMLE snipers are built on EFD rifles, although I know of one, & apparently IDS has seen a few, equipments built around BSA rifles. I suspect LSA variants existed as well, the scarcity/absence of identified examples these days just being a consequence of the much lower LSA production totals & therefore numbers converted in the first place, combined with the negligible survival rate.