Summary

A few things to customise the Worker Harrier.

The grip replacement initially came about because it seemed easier to print a replacement than paint the knuckle guard (when all you have is a hammer and all).

This also then left space to do an extended mag release so you can release with your grip hand.
There's two versions - 2 and 3. 2 is simpler, but 3 is more comfortable (though may need a bit of trimming/sanding to get it to fit