Greetings,
I have some of those devices. The fellow was in California and sold them as a kit. They arrived with the brass thread moulded into the plastic and you glued the pieces together supplying your own clear plastic powder hopper.
This was fifteen years ago and is all the information I can remember.
They do work very well.
We need to services of a Plastic Mould Maker on this Forum.
Cheers,
Dave