I found this item, which I am calling an ammo dispenser. It is NOT a magazine. It currently has WWI 30-06 ammo in it. That may or may not be the caliber it was intended for. There are no markings anywhere. It is spring loaded and dispenses one round at a time.
uff ... the inside is more complicated than I imagined
I assume that little hinged divider thing can be moved along the corrugated metal for different length cartridges? That would help explain why the spring leafs are so short.
Weird that there's not a single mark on it.
I tried searching for answers a little earlier and got nothing. May try again tomorrow. Can't believe it's a one-off, somebody must have made a few of these and sold them.