[kanuck]

BFT3, that is the inspirational pic I have been waiting for. Center exiting exhaust tips on a '74 RS bumper. Although I am probably going to trim the plate slightly as opposed to folding, your pic definitely shows that a plate that lines up with the top and bottom of the RS bumper (as opposed to hanging over), will restore lost feng shui!

So my final solution, (inspired by BFT3), will be to trim as little as possible off the top and bottom to make it line up perfectly with the RS bumper (unfortunately probably cutting just slightly more than the little trim piece that luccia suggested), and then having thin, black custom frame made from plastic or rubber (as acme911 mentioned) to finish the job and hide any raw plate edges.

Thank you for the collaborative effort!