Here's some pics from when I visited his house for a family reunion. You can see the shrunken head and me in the first picture.
As for the legality of all of it I don't know. Most of the indian artifacts were found before there were laws expressly against keeping finds. The stuff from other countries is more complicated, because apparently a nation can make requests to the US to get stuff back no matter how/when it was found. I doubt any of it is illegal in the sense of black market trade, because he's never kept it a secret. He's given tours to local schools and had numerous reporters write about him/his collection.