The latest available version for the Linksys EA4500 v1 (kirkwood) router is 19.07.1. I am not technical enough to create a build myself. Would it be possible for somebody here to create the build for 19.07.2 for this router?
If the git log is correct then your device is codenamed 'viper' and there are images available for that.
Doesn't help, of course. For mvebu (another platform Linksys used) there's a patch pending to revert to the actual customer device names.