Weeble Kneeble

Weebles wobble but they don't fall down!
Not too sure about this one though. Saw an image of a weeble which got me thinking...
Sourced imagery & hey presto this is what I came up with. Drawn with the mouse in illustrator using 2 colours.

Can anyone help me track down other covers in this book series? Were the covers done by the same illustrator?
Any help would be appreciated.