: You can access the source code and legacy releases on the iH8sn0w/iREB-2.0 GitHub page.
If you're looking to put together a piece (or a package) for jailbreaking an iPhone, specifically using iReb for versions or configurations that match "40x 41 421 rc3zip," here are some general steps and considerations: ireb 40x 41 421 rc3zip link