A quick search says that there a ton on thereDamn, that’s amazing. I wonder if they have any on eBay.
Fair warning, those keyboards tend to be a bit mushy these days. And mushy or not, they're certainly DNA collectors like @Amethyst1 said. The ice cube tray keyboards are quite possibly some of the most disgusting peripherals I've ever had the displeasure of disassembling and cleaning for other people