Where under the terms of a settlement a person is entitled by way of remuneration for his services as trustee to an interest in possession in property comprised in the settlement, then, except to the extent that the interest represents more than a reasonable amount of remuneration,—
the interest shall be left out of account in determining for the purposes of this Act the value of his estate immediately before his death, and
tax shall not be charged under section 52 above when the interest comes to an end.