You don't need an amnesty to sell the radio - just offer it to a dealer or sell it on Ebay. If you are not a ham you will find it hard to sell to any other ham (unless they are pretty new to the game or clueless). Maybe get a friendly ham to check it over and sell it for you? But there is no legal issue - anyone can own a ham set, or sell one though when you install one on a boat the rules are different.

Like lots of rules and laws, you are unlikely to be caught but these things tend to come to light when they want to crawl all over your papers after an accident, or if you upset someone..... It's your risk.

I am presently in contact with a specialist firm in Gib who help to ensure that you are properly legal wherever you are and they say that a lot of their business comes from ordinary people who have one fairly trivial contravention, get caught, then lots of things come crawling out of the woodwork.

It's like the copper who stops you for one thing then checks your tyres, tax, MOT, DL, insurance, wipers, washers, lights, horn,.... It hasn't happened to me but it has to friends of mine.