Above we see further conceptual sketch evidence of a proposed Pre-school line for Super Powers. No prototype examples have surfaced for these figures. You can see 4 figures above: Batman, Robin, Superman, and Joker. These pictures come from photocopies of the sketches.
Here you can see an additional figure: Wonder Woman. Old Batman was cut in half on this photocopy ;^)
This sketch suggests a Superman theme was kicked around. Supergirl and Krypto would have been awesome pieces! Lex Luthor doesn't appear as menacing in his childish form. These sketch photocopies and the conceptual drawings I have are the only evidence I've seen of the pre-school line to date.