So I got a bunch of the 5mm, 15-ball, 3/64" glide rings from Skiff. I tested them out in a bunch of current Kizers and that seems to be their new favorite size. My results are now posted on his compatibility list and I've got another order on the way.
While I don't have an Original, this is probably a safe bet. Just use calipers to measure your stock bearings. (If you don't have calipers, this is a good excuse to order an inexpensive digital set. It's a tool that will definitely come in handy sooner or later.)