(1) In a case where -

(a) a person who is entitled, as a result of an accident, to disablement pension (hereafter in this article referred to as an "existing pension") which is payable in respect of an assessment for a period which is limited by reference to that person's life, becomes as a result of any other accident subject to a loss of faculty in respect of which disablement gratuity would, but for this article, be payable, and

(b) the aggregate amount of the assessment in respect of the existing pension and of the assessment in respect of which such disablement gratuity would be payable would, if it were the amount of the assessment of the extent of the disablement resulting from the accident which gave rise to the existing pension, have entitled him or her to receive disablement pension at a higher rate than the rate of such existing pension,

if, at any time before his or her claim for disablement benefit is determined, he or she so elects, that person shall be entitled to disablement pension in lieu of the said disablement gratuity at a rate equal to the difference between the said higher rate and the rate of the existing pension.

(2) In a case in which a person who is entitled as a result of any accident to disablement pension who would but for the provisions of this sub-article become entitled in respect of any other accident to disablement gratuity -