Here are a few different Barbie bodies. By the way, ALL of these dolls came from thrift shops. The one on the far left had me very confused because of her strange arms, but now I know she was a "Poison Ivy Barbie" from the Batman series. Her arms are supposed to be more poseable, but I think they made a mistake with that idea. Her arms make her look like a Gumby figure! Also I thought I had found a vintage Malibu Barbie, but after doing some research, I reasoned she may be the 2002 reproduction.
The two on the right have the newer body which some people refer to as the "muse" or "belly button" body. The one in the middle has the old body which is pretty ugly....and she has perma-undies.
On Malibu Barbie's bum is imprinted 1966, MATTEL INC. U.S. PATENTED U.S. PAT. PEND.
MADE IN JAPAN. At first I thought that the originals were MADE IN TAIWAN....but then I saw a listing of 1971 Malibu Barbie having the MADE IN JAPAN marking. So I honestly don't know if she's an original or a repro, because she had no packaging or accessories except for her blue swimsuit. If anyone can clear this up, I'd be grateful. Yeah, you can't really see the writing in this photo, but I thought I'd try anyway.