Apparently this site has some. It seems to be current. http://www.gotkoi.com/koi_medication/fluke.html
Fluke tabs are a combination of organophosphate and carbamate insecticides. The same stuff they used in flea collars years ago. Most flukes have become resistant to both over the last few years.
What I remember about using Fluke Tabs years ago was how hard it was on the discus. Their color would fade and they would stop eating while undergoing treatment.
Once Prazi became available, most people stopped using Fluke tabs.