If I recently reloaded J41 do I need to uninstall and reinstall the addtional liveries?

Yes. The livery installer modifies a cfg file, which is restored to original after you reinstall the aircraft, and you cannot run the installer if it finds that it has already been installed according the windows registry. Therefore, you end up with the cfg file out of sync with the registry. This is a real pain but it is how MS designed it.