I thought I better start a new thread since we were diverging pretty far from the Lets See Your Master Mibs topic.
This was Bill's box and these are his pics too. @mibcapper
It is a lot like the Master #10, but probably even more rare.
An old fashioned "Lite Brite", just over 100 years old and not one of the 600 tiny clay marbles is missing - what are the odds?
Sorry for the less than ideal photos.