The belt buckle is half of a “tongue and wreath” style belt buckle is a period early 1850s California Gold Rush relic!! That one is known as the “cast miner” buckle because it is cast brass and depicts a gold miner leaning on a shovel with some mountains and a sun. This is one of the most highly sought after and coveted of all the California Gold Rush belt buckles!! Probably less than 20 complete tongues are known to exist (I found one back in 2018!!) and maybe a quarter as many complete wreath sections. Very incredible relic to have found in Australia!!! This and one other are the only ones I know of to be found outside of California, what an incredible journey it must have gone on!! I’m voting banner on this one.