I don't believe anyone in QLD does it now.
The only place I know of is Saintech in Forster NSW.
https://saintech.com/
Alternatively you could get the spray on silver kits from Angel Gilding. One small bottle of Silver concentrate can do about 20 mirrors. However Silver deteriorates quicker than aluminium and you may have to strip and respray every 2 years. Depending on how close you are to the ocean (salt in the air).
https://angelgilding.com/silver-on-g...ay-silver.html
Here is a set of videos showing the technique used by Peter Pekurar silvering the Vatican Mirror.
https://www.youtube.com/watch?v=NIg8...NoE31tmPGUebYg