Up close shots of its signature lines. I have read 2 reasons on how these were created. The first was these were made from being carved out by a spinning lathe machine, hence sometimes them being called “spun steel” ersatz. The other was from the dyes that pressed them out of the sheet steel.
The front and rear split pins that, along with the side posts, hold the liner to the steel shell. The pins seem to have been made from brass, with the rear split prongs having suffered from some corrosion.
Some of the markings I’ve found on the liner, including a name, the size marking, and although not clear on the last pic, a potential maker mark on one of the tongue that stitches the liner together. It might be from the company C.Henke of Witten, although a few other manufacturers have made these types of pickelhauben