I came across this on the Portland, OR craiglist yesterday. We have two BLM Sulphur Springs mares, and love them. We adopted our mare as a 3 year old directly from the BLM three years ago (she gifted us with a filly 10 days after we brought her home). She has not been an easy mustang to gentle, but well worth the effort. I emailed the seller (actually trainer posted on behalf of client) and this horse really sounds similar to our wild-born mare - a very intelligent horse that thinks outside the usual equine box.
If our barn wasn't full already I'd consider taking him, but I cant, so thought I'd post this here in hopes someone from this board can help place this horse in the right kind of home for him to flourish. Hope I didn't break any rules by posting that here.