I took more pictures of the speaker, grill, hardware and wiring route. Based on my findings of the rear deck with the grill off I am changing my earlier comments about being knock-outs to now being hand cut. Unfortunately, I was not able to match the screw, nut/washer or wire clip to any AMK hardware. The wire routing exits the right side of the trunk, down the right side rocker channel within a protective plastic loom along the rocker length and exits top of the kick panel, travels under the glove box in parallel with the antenna wire (and is also under the antenna wire retainer clips) and then exits and plugs into the fader control harness as shown in 67AIM U80/A2 view B.
I hope these pictures help. If you need further closeups let me know.
Mike