Vintage door knob jig - photo

Vintage door knob jig.

https://diqn32j8nouaz.cloudfront.net...e_fullsize.jpg


Previously:

https://www.homemadetools.net/forum/...904#post198695
https://www.homemadetools.net/forum/...847#post198462
https://www.homemadetools.net/forum/...740#post124087
https://www.homemadetools.net/forum/...193#post195778
https://www.homemadetools.net/forum/...034#post195086

How does this work? Not sure what I'm looking at here.

the two "holes" form guides for the outside of a drill powered holesaw - the one in the panel face of the door is for the knobset, the one in the edge is for the striker mechanism.