thickness gauge for Festool Domino DF500

There is a new version of this at https://www.thingiverse.com/thing:4462771

The Festool domino DF500 is a marvelous hand mortising tool which is calibrated for metric measurements only, so using it with North American standard sized boards (imperial measurements) requires a good amount of calculation, or purchase of an after-market thickness gauge that is sized for undersized plywood boards only. Thus the need to create an adaptation that would make it possible to immediately position mortic