I see the The green shed has 1m lengths of 3mm Aluminum 10cm wide, well they have them on their website, if they actually have any in stock is another matter.
https://www.bunnings.com.au/metal-ma...t-bar_p1063146
I guess this will suffice once notched with the Dremel.

I've got to go down there anyway to get a Air Compressor for the Air Brush, plus whatever else I usually see and think I need.....never ending story with hardware stores.

Hardware stores are to a bloke, what a shoe shop is to a female, although far more practical and nowhere near as expensive.