After posting a question in another thread, I've taken some of the advice proffered and gone ahead and installed the acetate viewing port.

I pre-painted the edges of the viewing port in the front deck, dipped the piece of clear acetate in Future (twice) and then super glued it in place on the inside. It worked! There was absolutely no frosting from the super glue, as you can see on the left side of the composite image above.
Seeing how that worked so well, I picked up a bottle of Micro Mask at the LHS (it's all he carries) and I brushed it on over the acetate, burying a piece of thread within it. If this goes well, I should be able to pull the masking off the acetate with the piece of thread, thereby eliminating the possibility of scratching it with the tip of a hobby knife.
Cheers,
Chris