This is probably the most painful step – fitting the infill. It has to just fit, there are no back and forth adjustments. But I cheated to keep my sanity. I shaped the rear of the infill, which wasn’t any fun at all but didn’t worry about the ramp or length. Once I got a good fit at the curve and sides, I drilled a hole for the strike button (1/4” x 20) in the body and infill, tapped the infill and bolted the infill into the plane. Then back to the mill to cut the ramp, the back of the plane and mouth in fell swoop. A bit nerve racking.
I used 30 minute epoxy to glue the infill to the body, which is a gluey, sloppy mess. I used blue tape to mask the brass (which sorta worked) and cleaned things up with naphtha (I’ll try white vinegar next). Epoxy was smeared all over the top of the infill, especially at the pointy end of the infill (to strengthen the very thin wood). Mill sawdust was mixed with the epoxy and used to fill gaps.
The front infill was just cut and glued, no milling.