Bueno, pues por fin han podido identificarla en el foro de Numista:
"A mule of the 1-cent reverse, with the Straits Settlements obverse showing Queen Victoria, has been recorded in brass - possibly deliberately contrived some time in the 1870s after Heaton got the contract to strike the Straits coins."
http://dniewcollectors.blogspot.sg/2011/11/sarawak-coins.html