Where before 1st October 1980 a person who is granted a gaming licence in respect of any premises entered into an agreement with any other person whereby that other person is entitled to use those premises after that date for the purpose of gaming, and the consideration for that other person under that agreement does not take account of the additional duty payable under section 6 of the M1Finance Act 1980 or this Act, as compared with section 14 of the M2Betting and Gaming Duties Act 1972, the first-mentioned person shall be entitled to recover from that other person such amount, if any, nor exceeding that additional amount of duty, in such manner as may be agreed between them (or, in default of such agreement, as may be determined by the appropriate court) to be fair in all the circumstances, having regard in particular to the extent, if any, to which while the licence is in force the premises will be or are likely to be used otherwise than by that person for the purpose of gaming.