Need help identifying vintage oily jigglers

[kidkosmic]

I recently purchased these three oily jigglers and cannot find anything about them online. Two of them have eyes similar to Russ Berrie jigglers, but on their backs, these jigglers are marked "CONCEPT '66." They are fairly large 5" or so. Any info / help would be appreciated. Thanks!

[kidkosmic]

To clarify, the backs of these jigglers say "Concepts © 66" and "Made in the USA." I'm including a couple of additional images.