What did the factory use as far as the package tray with the optional "single" rear speaker on '66 & '67 442 hardtops? Legendary offers one "blank" & one with 2 pre-cut speaker patterns?? I believe the single speaker was located in the center of the package tray.

Was there a ("mesh covered"?) package tray with a single cutout in the center?

 

You are correct the single speaker was mounted in the center of the rear deck. It had the mesh cover with no visible signs of the speaker showing.

I'm the original owner of the 67 in my signature. Also worked at an Olds dealer during that time frame and owned a 67 442 hardtop. Sad to say I sold that one. Kids do stupid things...