On 1856 October 22nd Australia Gold Sovereigns and Half Sovereigns were legalised for use in Ceylon by Proclamation of Queen Victoria. It was revoked by proclamation on 1869 June 18th with the introduction of Decimal currency for Ceylon.
The 1856 October 16th Proclamation of Queen Victoria was only published in The Ceylon Government Gazette No. 3,044 of July 25, 1857; The year of this coin.
The 1857 to 1870 Australia Sovereigns had Second Type of head engraved by L. C. Wyon. Older 1855 and 1856 Sovereigns of First Type had larger head engraved by James Wyon, as used in the Sovereign Minted in London.
According to Sir Robert Chalmers these enactments were ineffectual ; the Indian rupee remained the local standard of value, though its legality rested solely on the Governor's Minute of 26th September 1836.
Ref: The Gold Sovereign. by M. A. Marsh.
1999, Cambridge U.K., 2nd ed. 118pp. Illustr. colour
The Sovereign was scanned at 600 dpi and displayed at 300 dpi It was obtained in USA around 2000.