Vintage Mr. Potato Head toys are some of my favorite collectibles. Besides Mr. P-head himself, there are lots of related items to search for, including many knock-offs made during the early years of the craze. This set, Silly Billy, was particularly bold, even including the manufacturer's name and address on the box.
The contents appear to have been molded right from the originals, and the illustrations are virtually identical. Naughty, naughty. I can't imagine they got away with this for very long.
You can see lots more Mr. Potato Head knock-offs (and rare vintage Potato Head stuff) at www.mrpotatohead.net.