We've been succesfully blending our own fuels using methyl hydrate and or methyl alcohol mixed with 5% castor. I live north of the 53rd parallel and depending on the temperature and humidity I sometimes add just a pinch of 15% fuel just to smooth er out. Works very well in my OS46 FX. 40Rossi and 30cc OPS.
I'm not a chemist and I'm not certain what the chemical make up is of the methanol/ methyl hydrate/ methyl alcohol but I do know it works and its cheap. Methyl hydrate is available at any auto parts store and is used to dry out the air lines in semi-trucks.