I was looking for some a few months ago so I googled "eyelets" and found some manufacturers/dealers, but you have to buy 10,000 at a time.
I thought it would be a good idea for someone to buy them....maybe someone who has a business and sell them in smaller lots to poor saps like ourselves.
I haven't needed them since, so I kinda dropped it.
On another forum....it may have been this one...there was discussion on using copper or brass tubing and cutting and flaring, blah blah blah.....not for me.
A fellow forumite sent me a handful of them and I found out that you have to have them be about 1/16", at least, longer than the thickness of leather you're working with.
Good luck finding them, but they are out there.