Suitable Substitute For Testors Aztek Acrylic Thinner

[SAT69]

I've tried using water for thinning Microscale Micro Gloss and didn't get good results. Since Micro Gloss is water soluble, I decided to try using Testors  Aztek Acrylic Thinner to thin the Micro Gloss and it worked wonderfully. Problem now is that that thinner is no longer available. Thinned properly Micro Gloss sprays well and leaves the kind of finish I want, so I'm not looking to switch to another gloss, unless it's really necessary (I have three bottles of Micro Gloss). What would be a good acrylic thinner to use in place of Testors Aztec?