(1) For the purposes of this Division, money shall be taken to have been due to a mortgagee under, or to have been secured by, a mortgage at the time of acquisition of a mortgage interest only to the extent that, at that time:
(a) the right of the mortgagee to recover the money secured by the mortgage was not barred by a law relating to the limitation of actions; or
(b) the mortgagee was entitled to recover money secured by the mortgage by exercising a power of sale of, or other remedy in relation to, the interest in land subject to the mortgage.
(2) For the purposes of this Division, the interest due to the mortgagee under a mortgage at a particular time is the interest that would be payable to the mortgagee if the mortgage were discharged at that time, other than so much (if any) of that interest as represents:
(a) costs of re - investing the principal under the mortgage; or
(b) a loss, or possible loss, of interest on the re - investment of the principal under the mortgage.