THX Deldriver, that's the one missing from the pile, maybe in with the last 2 data sheets I did, both Inland 6 digits. I'll find it and grade myself.
USGI,
Remember Inland used both the horizontal and diagonal plates in this first block. Inland had 2 suppliers of butt plates. I know Seymour was one and thought to be the maker/suppliers of the square/horizontal plate.
The diagonals also used, I just can't remember the makers name......... something like C&G Co (?)
Charlie