(1)When an instrument brought to the [Deputy Commissioner] [Substituted by Act 29 of 1962 w.e.f. 1.10.1962] under section 31, is in his opinion, one of a description chargeable with duty, and,-(a)the [Deputy Commissioner] [Substituted by Act 29 of 1962 w.e.f. 1.10.1962] determines that it is already fully stamped, or(b)the duty determined by the [Deputy Commissioner] [Substituted by Act 29 of 1962 w.e.f. 1.10.1962] under section 31, or such a sum as, with the duty already paid in respect of the instrument, is equal to the duty so determined, has been paid,the [Deputy Commissioner] [Substituted by Act 29 of 1962 w.e.f. 1.10.1962] shall certify by endorsement on such instrument that the full duty (stating the amount) with which it is chargeable has been paid.
