I wish I did know who made them. The few I have came in a zip lock baggie, and there aren't many in the bag.
I read an article online about using a press and a die set to swedge pellets from lead shot. Seems like a waste of time for the .177s they were making. I have a small lathe, and these little buggers are proving hard to find. I may try an experiment and see if I can press a servicable pellet out. The ones I have don't look quite like a 'normal' skirted pellet. They look more like a tiny thimble. I think I may be able to press a thimble shape out of some lead flashing I have. If the lead will take the displacement without tearing, I will have the problem knocked. If the sheet won't work, I can try a piece of shot.
If the press doesn't work out, I won't build the gun. At least not in the 30. I will go forward with some sort of large bore air monstrosity, one way or another. I have all the parts (more or less) from a few years ago, then I never went through with it. Now is the time.