Where any person on applying for probate or letters of administration has estimated the estate of the deceased to be of less value than the same has afterwards proved to be, and has in consequence paid too low a court-fee thereon, the Chief Controlling Revenue Authority for the local area in which the probate or letters of administration has or have been granted may, on the value of the estate of the deceased being verified by affidavit or affirmation, cause the probate or letters of administration to be duly stamped on payment of the full court-fee which ought to have been originally paid thereon in respect of such value and of the further penalty, if the probate or letters is or are produced within one year from the date of the grant, of five times, or, if it or they, is or are produced after one year from such date, of twenty times, such proper court-fee, without any deduction of the court fee originally paid on such probate or letters of administration:
Provided that if the application be made within six months after the ascertainment of the true value of the estate and the discovery that too low a court-fee was at first paid on the probate or letters of administration, and if the said Authority is satisfied that such fee was paid in consequence of a mistake or of its not being known at the time that some particular part of the estate belonged to the deceased, and without any intention of fraud or to delay the payment of the court-fee, the said Authority may remit the said penalty, and cause the probate or letters of administration to be duly stamped on payment only of the sum wanting to make up the fee which should have been at first paid thereon.