But that’s the problem. I’m guessing this takes until whatever the copyright term is in the UK. In the US, that’s 70 years (maybe it’s longer now, IDK) after the death of the original creator. If it’s sold, that’s still going to take a long time because they’d likely be stuck in legal limbo just like this one is and take years to clean up anytime someone wants to use the IP.
In short, I don’t think unclaimed IP should be sold, it should either be claimed or put into the public domain, after a grace period. Imo, copyright duration should be much shorter, such as 14 years (original US copyright term) with an optional extension, and copyright should only be transferred once (exception for immediate family).