Sig Butyrate Thinner works fine for thinning Aero Gloss Sanding Sealer and all other "2nd Generation" Aero Gloss color dopes as well.
You can tell if the Aero Gloss dope in question is "2nd Generation" or beyond as it will NOT list Tricresyl Phosphate on the label as an ingredient.
First generation Aero Gloss has a VERY distinctive aroma compared to 2nd generation. I doubt many on this forum have much 1st Generation Aero Gloss; the formulation changed in the mid-1970's.
If you happen to have any 1st generation Aero Gloss, DO NOT attempt to thin it with commercially produced current dope thinner. It has ingredients that are incompatible. If one needs to thin 1st Generation Aero Gloss, I reccommend using straight Toluol/Toluene. Other solvents that are compatible with 1st generation include ONLY Acetone, MIBK, and MEK.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !