I found these cool looking 39mm, J. A. Ewing chip trays at a local coin shop. These appear (and feel) to be cast aluminum trays!

Each weighs in at 12 oz., when plastic trays weigh in at 5 oz. (The off-color tray is 1/2 an oz. lighter than the other 2.)

I have labelled the second image to better show the cast lettering information on the back of all three trays.

Thanks for looking!

Jim