Thanks for your comments, Opex. I imagine Peru doesn't have great wealth to splash around on military equipment and is obliged to 'make do and mend' (eg like Israel in the 60s). Other countries are doubtless in the same position, re-cycling as much as possible. Such countries would probably have relatively cheap labour on hand, too, making refurbishment an economical alternative to fresh procurement. This would also mean they dispose of surplus stuff less frequently - making these Peruvian M1s, perhaps, a relatively rare exception. Possibly they've re-equiped with second hand PASGTs? By the way, I'm just a little concerned the only evidence for these helmets being Peruvian (that I've seen) is the brendonshelmets website (although there the helmet is associated with a distinctive cover more easily attributed due to the camo pattern used). I'm not disputing the attribution by such a reputable collector but would like to find some more evidence if possible - especially photographic. It's all too easy to go along with hunches that become assumptions and I'm trying to be disciplined!