Thanks for the orange controller update. I'd be very interested in seeing pics or hearing how other collectors came across theirs, if/when you're willing to post!
Funny you mention the Dakota controller... I stopped by a thrift store between posting and reading your reply, and wouldn't you know! Dakota with breakaway cable. Different than the Duke breakaway. Picked it up for $2.99.
The [H] tour is pretty cool... I was very excited when I found it. Just had a low-res pic of the case, before. I've been meaning to figure out which MS building it's in. I hope it's still there. I suppose it's possible that my orange controller and the one in the case are one and the same.
Contacting some of the staff named in that post might be a good source of rare original Xbox products info.
A couple other cool controllers in there. The silver one looks one-off... have any idea what the blue one is?