(1) A trustee unless expressly forbidden by the instrument (if any) creating the trust may in addition to any other mode of investment for the time being authorised, invest any trust funds in his hands whether at the time in a state of investment or not in:
(a) any of the existing Parliamentary Stocks or public funds or Government Securities of the late United Kingdom;
(b) any of the Parliamentary Stocks or public funds or Government Securities of Great Britain;
(c) any of the Parliamentary Stocks or public funds or Government Securities of Saorstát Eireann.
(2) In the foregoing sub-section the word "Parliamentary" is to be construed as referring in clause (a) to the Parliament of the late United Kingdom; in clause (b) to the Parliament of Great Britain, and in clause (c) to the Oireachtas.