It would be
pretty trivial to build a vacuum forming mold and use
ABS plastic... >
Could you elaborate on this? Maybe a website with this procedure
explained for unenlightened people in the World of Plastics(tm)?
There was/is a book, soemthing like 'How to build a pastic vacuum-forming
machine'. I am pretty sure the author was one of the Gingerys and that it
was bulished by Lindsay Books.
The device is vey much home-made using cooker elements, etc. I am not
sure if it would do for making thse trays (and I've not made one -- yet),
but it would give you an idea of what's involved I think.
-tony