[unclebrad]

Well, I went the poor man route and converted a couple baking pans that I found at Big Lots (The hotel pans come in standard sizes and the long sides were too long while the short sides were too short. Baking/oven pans come on all sorts of sizes.) the metal is fairly thin, which makes it easy to cut and bend, and one it is screwed down it isn't flimsy.

Also, I used rivnuts, based upon dsraven's suggestion. that meant that I didn't need to cut the opening any more to create an edge for the clip placement that I had planned to use based upon stepside jim's post.

Granted, it isn't as professional as stepside jim's, but it does the job.

Some pictures - 1. cut and painted, with rubber edging. 2. rivnuts in place. 3. in place - still needs a couple screws.