Retrospective payment of VAT/duty?

Hi A USA citizen visiting the UK brought a small clock (100 years old, value £300-£500) into the UK for study/assessment but has now decided to donate it to a museum. Since this would be a gift, should he pay VAT/duty? If so, how would he go about doing this? Thanks 

Name removed admin .

Hi,
You can hire a person or business to deal with customs for you such as customs agents or brokers who can do import declaration for you and help you pay the customs.
Guidance is available at: Get someone to deal with customs for you
Thank you