Thunks and Grunts in hiding

You may not know this, but the album covers in Thunks and Grunts are not the first time the cast have appeared on record sleeves. They've actually been on lots of famous album art throughout the years, but you've probably not noticed them before because they're pretty good at hiding. Here’s one of them:

If you've seen them on any record sleeves please do let me know - otherwise, keep on supporting Thunks and Grunts on Kickstarter: http://kck.st/3mKI7cL