H. M. Customs
Here’s a nice example of an Her Majesty’s Customs button from the Victorian era. Lesley from the Hammond-Turner website (https://hammond-turner.com/ ) tells me it dates from 1835-possibly the 1870s.
They exist with the VR, for Victoria Regina, in various scripts, including a block serif style as seen above, a ‘Gothic’ (also known as blackletter) font and the intertwined monogram type (see below).
These were a stock design from the U. K.; however there were some at least customised for the colony of Victoria (as seen in Cossum’s book, page 69), and some the included a naval anchor. Below are a group of South Australian customs officers at Port Adelaide in 1885.
In 1859 Custom Officers were required to buy new uniforms, only to be told they looked to alike to Naval uniforms, and to refrain from wearing them!
I am not sure if officers in all colonies had uniforms, although there is mention for Tasmania, West Australia, New South Wales as well as South Australia. At some stage, possibly Federation, the uniform seems to have been discontinued apart from a cap and badge. This caused problems but was not remedied for decades.