In Australia "Op Shops" (as they're called here, short for "opportunity shops") are all over the place. They're just a 2nd hand shop which takes in donations and resells the things for charity, usually. Similar to Good Will or Salvation Army shops in the US.
Anyway, I went into a local op shop and found 2 small glass tanks! One is pretty much exactly like the one Leroy is in now.... about 6.25 gallons with rounded front corners and no edging, or trim, on the corners nor along the top edge. It was in excellent condition, although it needed a good clean and a new lid. The lid it has is just a piece of glass that someone obviously just sort of cut somehow to roughly fit... but it doesn't really fit, it's too wide.
The other tank is smaller, I'm guessing only about 2 gallons max. It's a cheaper looking tank and has black trim on 3 of the 4 vertical edges. It has a decent, proper glass lid.
So, I've got them in my carport now, filled right up to the top with water and white vinegar. The nicer one has a bit of water deposit around the top. Also, hopefully I'll check tomorrow after work and neither will have leaked.
A good scrubbing and they'll be very nice I think! Yippee!