Rivet bearing block onto center aileron hinge bracket. Place fairlead guides on 2 OB flap hangers and IB aileron hanger. Put paracord in place of control cables to deterimine location of fairlead guides, cable placement, and any interferences. Found spacer blocks behind aileron pulleys to be too short as cable would rub ob next IB rib. Replaced 3/8" spacers w/ 3/4" spacers, gave 1/8" or better clearance to rib. Checked flap push rod to cables clearance, etc. Found that center flap hinge requires 5/16" bushings, ordered from McMaster-Carr. Lots of research on correct parts for each control installation, etc.