Fabricated second bracket for heat diverter. Test fit; determined rivet hole placement; drilled first hole; fit; laid out second hole; drill; fit; etc. Repeated procedure until all rivet holes were drilled. Modified shape of diverter and cable slot for clearance. After fit was dialed in, dimpled all rivet holes in diverter, diverter brackets and cable clamp bracket. Prepped and primed mating surfaces of brackets and riveted brackets to diverter. Riveted diverter assembly to cable clamp bracket. Bolted down cable in Adel clamp and attached cable to flapper lever. Bolted upper diverter bracket to firewall angle, sandwiching wiring harness retainer between bracket and angle, pinning wiring harness in place. Checked cable function and heat diverter fit; all ok.