This publication documents all of the passengers that departed Hamburg in 1853.
It includes a Carl and Friedr Thiele on the Caesar Godfrey from Hamburg to Port Adelaide and Sydney.
It does list the Wilhelmsburg to Melbourne on 24 August 1853, but has no passenger information – saying no records for departing passengers exists for ships in the first half of 1853. However Victorian immigration records detail the passengers that arrived on this voyage, including Johann Gottlob Thiele.
See if any other ancestors are in this document.
I see that ancestory.com is available in some libraries:
