eBay seems to have none. Arcadeshop the only place now? Any equivalents of this equivalent out there? I see they are 30KV rated and there are some available with that rating but don't know if they would fit the boot.
None of the other replacements out there are the right physical size. You can spend half a day figuring out a way to messily silicone something together, or you can just get the right diode.
Though most of the time, the diode just needs to be cleaned. I only actually have to replace one in maybe 20 cages.