I have a military youtube channel called JonBoy09. I am always adding items to my military collection and making new videos. I also from time to time make informative videos to help other collectors with information they may be needing. I made a couple videos earlier this year about how to date/determine era of helmets using the heat stamp. I believe these videos can really help people out. I did a video first on dating helmets from World War One - World War Two and then the second video is on dating helmets from Korea - Vietnam.
Here are the links to those 2 videos. I hope they are helpful to you. If you enjoy my content, I would appreciate it if you subscribed to my channel. Thanks