Hi Kelly, thanks for your response.
Info on Thomas Snrs. D/C was provided by an employee of the Liverpool Asylum - I assume from details provided on his admission - unfortunately these records no longer exist. Age on D/C, Jun 1911, was given as 83 - Thomas was born Nov 1827, so age is correct. Wife is given as Margaret Aitken, also correct and the only children listed are Thomas and James Malcolm, the two he left Daylesford with.
Thomas Jnrs wife remarried. Her death certificate gives both husbands and lists all children from both marriages. I only have the M/C for my grandfather - he correctly gives his parents as Thomas Malcolm and Elizabeth Cugley.
The info on the 1947 D/C - the age is wrong, the place of birth is wrong and the certificate states this Thomas had been in Qld for 36 years. I found his arrival details - together with wife and 4 children - in Brisbane in 1911 ex "Torilla". Informant was his son, Thomas Wishart Malcolm.