I am not taking sides here but if it is unusual, usually comes on cheap bikes, there must be loads about. I have never seen one or anything close and i do look on ebay etc regularly. The seller has spent some time writing the ad and i don't think it is fair to abuse him/her as they have provided the info that has sparked the interest.
It may not be worth as much as the asking price, but it is interesting and could be worth some money. Bearing in mind that used stuff which you can buy every day can be £20+ for 600 stuff for example so £17 seems cheap for something unusual.
So GLWS!!!!
Richard