Honda V4 powered, interesting?
http://www.arielmotor.co.uk/mobile_2/ace.html


Something not balanced visually (to me) about the "Bobber" (the one with the girder front), but I find the telescoping fork version appealing.
That unique appearing frame is machined (not cast). Seems like there would be a lot of material wasted (presumably recycled) in the process, give the size of the parts (before welding) ...
Guessing it will price in the Bimota range of "bespoke" ...
On that note, there's also Hesketh's latest, the "24" (Hunt's #):

http://www.heskethmotorcycles.co.uk/hesketh-24/