I can't figure out how to get it linked here but if you search IG for [MENTION=199133]the[/MENTION]blandbicycle you'll see his recent iteration. There have been many before and likely many after, although i don't know how it would be better than Chris's. There have been frames made with adjustable headtubes as well but i dont remember who did it...Rabbit Fighter maybe?
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https://www.flickr.com/photos/54319503@N05/
http://www.draper-cycles.com