Next couple of pics represent the trimming of the motor stick. The top of the fin sets the thrust line, the top of the motor stick sets the angle of attack for the stabiliser.

Glued the assembly to the back of the plane. Being as straight as possible is ideal, of course, but there's a chance to correct any straightness issues when the ply keel is reinforced in the next step. This is basically packing wood/depron around the keel bottom in the second picture. Strength also comes from the keel being glued to the bottom sheet. This all makes a nice strong toque-box to take the forces of the motor both thrust and gyroscopic.