I have been able to find very little about this puzzle online short of a link to an eBay auction that is long over. The pictures from the auction are long gone so I am left with what little information I have been able to piece together myself. What I do know is that the puzzle was made by Playskool in 1976 and when all 23 pieces are together, it measures approximately 32" x 40.5". I was able to determine that this puzzle was sold in a box (as opposed to a plastic bag of some sort) so, of course, I'm on the lookout for an image of what that box looked like.
The illustration itself was done by Joe Mathieu -- who has done fine art work for Sesame Street products since the early 1970's.
The coolest aspect of this puzzle that I found was in the fact that the window pieces are interchangable giving kids the opportunity to mix and match the locations of six of the characters.
I'd love to learn more about this puzzle if anyone has any more information...