(12) A woman who is entitled to receive widow’s benefit under the legislation of Guernsey while she is in the territory of any other Party shall not be credited with a Class 3 contribution in respect of every week during which that benefit is payable to her, but shall be credited, for the purposes of entitlement to retirement pension or death grant, in respect of each year during the whole or part of which such benefit is payable, with a number of Class 3 contributions equal to her husband’s yearly average of reckonable contributions at the date of his death. If the rate of retirement pension payable to such a woman would be less than the rate of widow’s benefit formerly payable it shall be increased to that of the widow’s benefit.