Agree great article, here's my 2 cents.
page 89. BR hammers listed as Rock-ola, CCNL 372-12 article by BQ offers evidence that these are replacement hammers made by Bruner/Ritter
page 160. says Springfield Armory (SA) is one of the manufacturers of the M1 recoil check, Springfield Armory Developed the recoil check but it is not believed they ever manufactured any. He also leaves out National Tool and Die (NLD) as one of the manufacturers. ref CCNL 155-5 article by Marty Black (page 156 of 8th Edition)