I was never able to solve more than two sides. The two that I solved would get screwed up if I tried to solve another!
I did know how to make dots on all six faces and dots on four faces. I could do alot of checker board variations.
The only way I could "solve" it was to take it apart and put it back together again. But that's OK, I needed to take it apart to use petrolium jelly and lubricate it anyhow.
Back then you had to be really smart to figure it out. Today you just have to memorize some pattern.