This is THE website for information regarding obscure, rare and "forgotten" weapons. While almost all of the review and write-ups on the site are for firearms, there are a few great write ups on accessories and attachments, my favorite being the video review on WWI trench armor.
ForgottenWeapons also has a YouTube channel, in which he visits auction houses (Mainly Rock Island and James D. Julia) and collectors to review many amazing pieces of war and peacetime history. Recently, ForgottenWeapons had the opprotunity to review a prototype Pancor Jackhammer, which is possibly the only Jackhammer still surviving!
There are many great reviews and articles on the site. I highly recommend anybody who is interested in firearms or history to visit Forgottenweapons.com for accurate information and great videos.