For the purposes of section 8(1) of this Act, a superior (or, on or after the appointed day, a former superior) who receives, or has at any time received, from a third party an amount collected in respect of feuduty from and remitted to the superior (or former superior) on behalf of a vassal (or, on or after the appointed day, a former vassal) may require the third party to disclose the identity and address of the vassal (or former vassal) and, in the case of remission as a part of a feuduty, the amount so collected from the vassal (or former vassal); and the third party shall, in so far as it is practicable for him to do so, forthwith comply with that requirement.