(a)any such instrument not being an instrument chargeable with a duty of [twenty paise] [Substituted by Act 29 of 1969] or less than [twenty paise] [Substituted by Act 29 of 1969] shall, subject to all just exceptions, be admitted in evidence on payment of the duty with which the same chargeable, or in the case of an instrument insufficiently stamped, of the amount required to make up such duty, together with a penalty of five rupees or, when ten times the amount of the pro per duty or deficient portion thereof exceeds five rupees, of a sum equal in ten times such duty or portion;
