The original seller had a huge clearance of his remaining stock years ago. I don't remember the exact time but it was probably around 2005 or so. I really doubt it will be easy to find a set.
In all honesty the balls were not high quality, the star/stripes and etc were good, molded in but the resin wasn't great. I don't know for sure but I would guess they were a lower quality phenolic. Not terrible but not great. They felt kind of how the old coin op cue balls felt if that makes sense.
It's a great game, you can play it with stripes/solids if you can't find an original set.
Toward the end, the seller also was just selling boxes of 16 of the same balls once the kits sold out. He also sold 8 ball kits.