I thought you might like to see what a Mills type webbing loom looks like. I visited the production facility in India where my repro Mills equipment is made. This loom looks like the one in the grainy photo in the pamphlet about Mills equipment history. I have no idea how old this one is, looks like it has been producing webbing for quite a while. With this machine my webbing expert has been able to reproduce exactly Mills equipment features such as woven on pockets and pocket dividers, double woven bottoms, and variable width webbing. I am impressed.
Spectacular. I had no idea that Mills looms were still being used anywhere. Here is a scan of the original loom photo you mentioned, from Albert Lethern's The Development of the Mills Woven Cartridge Belt 1877-1956. That book was produced in 1956 and the loom in this photo maybe from that period. Yours looks to be quite a bit earlier than that!