Thanks for including a photo of the actual engine. Really helps.Brian,
The two drawing are in the instructions and the photo of the engine used in the Flyer. The "feet" are what the engine rests and are used to attache the engine to the wooden mount ("logs") that is part of the wing structure. drill out the lugs on the engine and match drill in the correct location/orientation on the engine mounts. I'm guessing there is hardware provided to install the engine.
This build thread has a lot of helpful photos including the engine installation the should be of some help.
1/16 Model Airways Wright Flyer - FineScale Modeler - Essential magazine for scale model builders, model kit reviews, how-to scale modeling, and scale modeling productsFineScale Modeler magazine - Essential magazine for scale model builders, model kit reviews, how-to scale modeling, and scale modeling products.cs.finescale.com