I settled the dispute with the seller today, he took me up on my proposal of £50 refund for the electronics not being as advertised/misleading advert. And £100 for a new spindle.

All the 0.8kW spindles on eBay have the same advert promising german bearings so I just picked the seller with 100% feedback.

I can also get some new bearings to see if they fix the duff spindle.