Ad-Lib Crossword Cubes by E.S. Lowe 1975
1975 edition in original box with original cardboard insert. Players roll their 13 letter cubes and then arrange them into words crossword style before the timer runs out. Once time is up, players score their words. They then close the lid to their box, gently shake it so that the words are mixed up but the letters remain the same, and then pass it to their opponent.
Players then reset the timer and again arrange words from the letter cubes, essentially trying to do a better job of it than their opponent since they are using the same letters. Highest combined score from both rounds wins.