"Oh, that's just permatex, Officer"
The single screw hole on the right-side is the set screw for retaining the control coil ferrule (that puck-shaped thing soldered on the end). On the left side you will find the two wire holes, each with two holes for the switch screws. Inboard from one of them you will see a third hole identical to the right-side retainer screw for holding the advance coil in place.
Apparently you are lucky to only need one button and one flipper switch. If you need an accessory switch for spotlights, scanner, VCR, etc., then little cad plated screw clamps were used with external wires, and a switch housing witha hole in it. These are also available.