Hi Longdog.
First of all Buells is Harleys as far as we're concerned!
As to Riders; I spoke to senior H-D people at the recent Presidents' Meeting in Lithuania ( if you're not an HDRCGB Club member this'll mean nowt to you but click on the triangular logo on the homepage for details) and they confirmed that Riders had dipped out because they'd effectively been messing H-D about. HD-UK are still actively seeking a dealership in Wales and are fully aware that they're missing out on business because there isn't one.
I would not be surprised if Riders sell and service second-hand Harleys and Buells in Cardiff , but my understanding is that it will be a Ducati and BMW dealership.