eBay protection should cover this, or at least paypal, under not receiving the items that the seller claimed to sell.
Yes, you would be covered by eBay buyer protection, however, if you didn't live in the UK, you would be responsible for footing the return shipping cost. In order to force a refund, the item would have to be sent back with online viewable tracking and proof of delivery. For an international shipment, that can get very expensive. Even if the board turns out to be a standard HHKB, that was still a pretty good price. I personally wouldn't have taken a chance given the inept description, use of a stock photo, and the fact that the seller has a negative feedback mark on his record.