Duster Dash Mystery- Name that missing item.

I'd say go ahead and fill them in. I've seen hundreds of A-body dash frames and that doesn't look like anything that I've ever seen. You didn't mention what year your Duster was though and that might be a clue. As for the clock, the digital clock wasn't even in the Chryslers until that late 70's. The early clocks were mechanical with rolling numbers.