That is NOT how to attached the M1910 hook hangers. I realize people do it that way because no one told them the right way. Even Soldiers who used the system did it wrong because its harder to do it the right way. When you do it the right way the ends of the M1910 hangers are not exposed and don't snag on you or other gear. The ends are on the inside and the bends are facing down. The belt holds the gear in place by putting pressure on the M1910 hanger.
Need to be careful on primo condition stuff might be Chinese repo stuff and they will put on the 60s-70s dates and leave off the made in China prints to rip collectors off. many butt packs get torn after a while because they were not made tough enough and a lot of weighted stuff was put into the pack. For my Vietnam collection, I've been focusing on the night vision stuff. last year I got a working AN/PVS2 scope with adaptors for firearm use and got through the mail today a Meta scope that was made for Israel, but was used in Vietnam for my collection, since I also like NV stuff.
There is a lot of photos of manual pages in a book called grunt. I just used that book Ave some photos online. I don’t know the specific manual i guess