There are two for sale over on gunsamerica.com. Also, watch on gunbroker.com the original Whitney's come up every so often. I searched for quite a while a couple of years ago for an original, but ended up with a really nice browning buckmark instead. Typically they go for about $400-$500 in nice shape. Good luck in the search.
Yes, I have seen the one's that are out there, too bad the one on GA that is kind of reasonable had the nasty spot on the frame. I'd almost go for it and have it re-blued if it was a bit cheaper. I'm kind of holding out for a $350/$400ish one in nice shape. Jim