RedDog, thanks for the link. As it was, the bidding had ended on the 3-piece grill set. However, as long as I was perusing eBay, I found an OEM lower right (I'm dying to say opening) grill.

I have an interesting problem on the right side in that the mesh grill wants to ****, because there's not enough room top to bottom. I turned it around and tried it on the left side and it fit fine, so nothing wrong with the grill piece (as I assumed would be the case).

I'm now guessing that this grill piece has been missing for a long time and perhaps the surrounding plastic might have moved around since there was nothing to hold the, ahem, opening's shape.

Biba