FOUND - truffle shell filling/sealing tray. (WAS WTB - truffle shell filling/sealing tray.)
I put my money where my mouth is and bought the Pastry Chef one. It's not metal, it's a hard plastic, but seems to be high quality.
@KonnyZsigo - thanks for finding this one. There are many options out there and I stopped at the first one I found.
Yes... that is exactly what I'm looking for...!