(1) Where two or more policies are effected by or on behalf of the assured on the same adventure and interest or any part thereof, and the sums insured exceed the indemnity allowed by this Act, the assured is said to be over-insured by double insurance.
(2) Where the assured is over-insured by double insurance--
(a) the assured, unless the policy otherwise provides, may claim payment from the insurers in such order as he may think fit, provided that he is not entitled to receive any sum in excess of the indemnity allowed by this Act;
(b) where the policy under which the assured claims is a valued policy, the assured must give credit as against the valuation, for any sum received by him under any other policy, without regard to the actual value of the subject-matter insured;
(c) where the policy under which the assured claims is an unvalued policy he must give credit, as against the full insurable value, for any sum received by him under any other policy;
(d) where the assured receives any sum in excess of the indemnity allowed by this Act, he is deemed to hold such sum in trust for the insurers, according to their right of contribution among themselves.