How Much is a Football Worth

A client did some work for a Premiership footballer. Payment was requested and made for the services rendered, but he also gave our client a gift in the form of a football that had a number of well-known signatures on it. Circumstances are such that this ball is probably now worth more than £10,000.

Is my boy taxable on the original receipt of the ball at all? If so, just on the £20 value of it as a ball or on its inherent value at the time (£2,000?)?

And regardless of whether he owes income tax on it, would it then fall to be sujected to Capital Gains Tax or could it be treated as a chattel and therefore escape any CGT?
Marion Morrison