clay Permoplast 1940's as found

This delightful box of clay is shown as found as I strongly suspect the packages that came with it are not original. the box is from the 1940's and upon doing some research found out that the original clay did not harden and could be used again and again. The original price of 25 cents is written in pencil on the back. the box itself measures 7 3/4 x 5 3/4 x 1 and is in nice condition showing the children playing with it. Inside the box are 4 wooden blocks that could probably be pressed into the clay. Please look at the photos and ask questions before bidding as there is no return on it. Payment is due four days after the end of the auction. Upon receipt, I try to ship within two days.