Click the link to download the folder, unzip the files to your computer to open.
A fun project to make for your own use, not for resale.
Optional materials list
PUNCH MATERIAL MCMASTER-CARR #3009A132
TUBULAR LEVEL VIAL MCMASTER-CARR #2148A67 (could find very high end ones elswhere.)
THUMB SCREW MCMASTER-CARR #93585A055
RETENTION 0-RING MCMASTER-CARR #9452K18
Level vial could be epoxied after installation, through hole needs to be perpendicular to be accurate. Consider machining base of V afterwards.