On ebay Robert Ravit, commonly known as thelordsgym, sells prehistoric figures I've seen nowhere else. He's sold me some lead figures of wooly rhino and elasmotherium I was completely unaware of. I lost one auction for a marx purple Trex, and a marx peach-colored iguanodon, I've seen no where else. (the iguanodon, and the rex). He recently had a WHITE invcta T-rex, and two mpc deodcicharus in unheard of yellow and grey colors. I just won an auction of his for three unheard of megatherium figures. The two smaller ones resmeble the small habititat earth mammals. One is black, the other gray and brownish-orange. They are slightly crude, thouhg. The bigger megatherium is hollow,(as I expected) but is greatly detailed and very well-made--but by whom, I do not know.
I don't mean to spread any discontent, but I have two of those three--they are all made be Wild Republic (formerly better known as K&M International, and currently known as the scourge that makes those stuffed animals with Velcro hands). The small ones are from Ice Age Toobs; the light coloured one is currently available in most gift stores. The black one is, indeed, out of production. The large one is from a set that came out last year (same as the current incarnation of the toob). They are sold as boxes, or individually. Again, they are available at most museum stores, many toy stores, and several online stores. In other words, two of those are not rare or hard to find. To be fair, he never actually claimed they were.
As for where he gets this stuff--trading, trading trading. And also buying. I have been dealing with him for about 4 years now. I've lost count of how much stuff I've sold or traded to him, only to see it come up on Ebay, or find out he sent it to a mutual collector friend.