Members of the Forum,
Apologies for my redundancy, as I believe this article was previously provided for the information of the Forum. A few years back I compiled the following article for the readers of my blog page. Given the post's question, thought it might be helpful to reintroduce it;
https://arnhemjim.blogspot.com/2015/...e-helmets.html . Hopefully this may be of some assistance.
Arnhem Jim aka Arnhemjim
Arizona Territory