This is a classic case of missing the point and shooting the messanger.

I am not angry at all. I am simply pointing out some of the issues that will be cleaned up in due course by the AI. An (electronic) trail of paper and self assessments submitted clears everything up.

Selling off a private collection is a business activity and whoever suggested it is not has given you some duff advice. You buy the items and sell the items exactly the same as any other business and if a profit is made it will be in your self assessment tax return and everything is fine. A few items a year, or £1740 in income, which is easily found on eBay and nobody will assess you. Similarly, if you have a service business and only make £1k in profit, you dont need to declare that. 

The topic is headed eBay is dead. I dont think it is dead. I just think there is going to be a lot of rationalisation very soon. I see the new rules on postage through an OBA and on eBay and other platforms and I think the old way of thinking is based on some wrong assumptions. Yes, I may be wrong, but I would think long and hard about where I acquired any private collections or inherited assets and what is the potential tax burden.