Bunnings is not necessarily the place to get buy shellac IMO. Also, you want to be sure you buy "dewaxed" shellac flakes, which IIRC, tha Feast Watson ones at Bunnings are dewaxed despite not saying so on the package.
The best places to source good (fresh) shellac flakes are proper woodworking supply stores. Many will have a choice of flakes or "buttons" and a range of colours.
When it comes to dissolving the flakes, you want to source methylated spirits that are "industrial" (100% Ethanol) not the 95% Diggers you'll get at the supermarket (or Bunnings).

I'll post more on this later, I need to go out for a while...