This one is located in Ohio. Don't remember which part but I'll contact them and see if they're willing to show it to you.
http://www.hallgtc.com/hall_010.htmThis one is located in New York and I was contacted a while ago by them saying they wanted to sell it but they never sent me the details. I'll ping them again to see if they still have it.
http://www.hallgtc.com/hall_005.htm