I made a tool to stamp these out in silver, it was a laminated block
that you fed a strip of metal into the side, this was then cut
through and pressed over an inset bulge to form the cup in one
strike. The cutting tool was a tube with a recessed end, held in
visegrips, You then ejected the cup with a rod pushed through the
tube. Quite fast to make, no special equipment to make it, I hardened
the plate that cut the disc, and also the tube, but not too hard. I
could look it out and let you know sizes if you like.
I think I made two in the end, a 4mm and a 6mm. The size of the disc
has to be correct to make a sufficient wall height.
It had three layers, the top one was a guide with a slot to feed in
the metal, 6mm, the next one hardened tool steel, 6mm, the next a bit
thicker, 8mm, to carry the shape to form the cup, so the cup is made
with the hollow facing down. It was all held together with a couple
if 6mm bolts threaded into the bottom plate.