I've only just caught up with 37's posting here - Yet another M1 clone shell, with a twist of navy - which I must have missed back in 2012. Very useful commentray. I do struggle to understand the provenanve of those magnetic shells with the smelly red liners. I have been particularly baffled by the fact that in Anders Skotte's book there is a paragraph referring to the specification of the M48;
"The helmets M48 are to be made in magnetic manganese steel as stipulated in USA specification MIL-A-13259. This specification may, however, be departed from if the finished helmet meets the requirement of being non-magnetic, and passes ballistic tests ...." etc etc.
OK, does this mean that it was acceptable to make the helmets from a steel that was magnetic *before* finishing, and that the end product was expected to be non-magnetic, or that it was acceptable for the shells to actually be magnetic all along the process into use? If so, how can we tell which were the military issue helmets which we have assumed must be non-magnetic?
Is there any chance we can somehow collect all the useful knowledge on these Danish helmets - especially the M48 - in one place?