Any reference in any law, deed, instrument, security for money or other document or in any contract or agreement, whether in writing or not, and any reference in any other manner whatsoever to an amount determined on the basis of the coins specified in the Schedule to the Coinage Act, 1922 (Act 31 of 1922), shall be construed as including a reference to an equivalent amount determined on the basis of the coins specified in subsection (1) of section 16 and in accordance with the respective values of such last-mentioned coins in comparison with the coins specified in that Schedule, as set out in subsection (2) of section 15, and any such reference to an amount determined on the basis of the coins specified in subsection (1) of section 16, shall be construed as including a reference to an equivalent amount determined on the basis of the coins specified in that Schedule and in accordance with the said respective values.