Just a heads up that I found out that ProBoat (602 Bascomb Commercial Pkwy, Woodstock, GA 30189) sells pretty much any VP Fuel needed, included MS100 which is 100 octane with 10% ethanol unleaded with a stoichiometric ratio extremely close to pump gas with 10% ethanol (13.9 vs 14.0x for pump), meaning its safe to use without a retune.
Using some myself mixed with 93 pump gas, car runs great with it and it's cat-safe.
They are open Mon-Fri from 8am to 6pm I believe.