I am interested in getting a couple of trays. The Carlisle 645007 fits the bill for one of them. Do you have a similar tray that measures from 12 x 16 to 12 x 171/2?
Carlisle only has seven Festival tray, the closest in the measurements you want is a 13 x 19-1/2 (model 643901) or a 15 x 10-3/4 (model 645007). Cal-Mil has an acrylic tray that measures 13 x 18 (model 325-13-12, item 231824. Hope this helps!