(1) Where there has been a loss in respect of any subject-matter not expressly provided for in the foregoing provisions of this Act, the measure of indemnity shall be ascertained as nearly as may be, in accordance with those provisions, in so far as applicable to the particular case.
     (2) Nothing in the provisions of this Act relating to the measure of indemnity shall affect the rules relating to double insurance, or prohibit the insurer from disproving interest wholly or in part, or from showing that at the time of the loss the whole or any part of the subject-matter insured was not at risk under the policy.