Longer arm to clear ARC enclosure acrylic panel

Remix of the fantastic remix by bgreat adding 4mm of length to clear the acrylic cover on the ARC enclosure.  The original made it past the case cover corner, but not the extra 3mm for the acrylic sheet on the outside, this remix adds the necessary length to work with the shell and acrylic in place.  This version does not require a threaded insert, an M4 screw can be directly screwed into it.