Whenever it is proved to the satisfaction of such Authority that an executor or administrator has paid debts due from the deceased to such an amount as, being deducted out of the amount or value of the estate, reduces the same to a sum which, if it had been the whole gross amount or value of the estate, would have occasioned a less Court-fee to be paid on the probate or letters of administration granted in respect of such estate than has been actually paid thereon under this Act,

such Authority may return the difference, provided the same be claimed within three years after the date of such probate or letters.

But when, by reason of any legal proceeding, the debts due from the deceased have not been ascertained and paid, or his effects have not been recovered and made available, and in consequence thereof the executor or administrator is prevented from claiming the return of such difference within the said term of three years, the said Authority may allow such further time for making the claim as may appear to be reasonable under the circumstances.