1: Both WD-1212 were drilled #11 according to the dimensions shown. 2: 7/8" I.D. CS-G405 Spaccer was installed on both control sticks. 3 & 4: Both CS-G405 control heads were pilot-drilled #40, then it was posiitoned on top of the previously installed spacer and clamped together 5: The hole on the control head was used to match-drill #30 the spacers, the control head was removed and the parts were deburred.