Rather than cobble something together, it would be best to take this 3 minute read to get an understanding as to why ethanol is problematic for older vehicles https://driving.ca/auto-news/news/higher-ethanol-fuel-and-classic-cars-dont-mix/wcm/1731c86a-a0d1-46ea-9809-49bed0025cbc/amp/

The bottom line is that the fuel systems in older vehicles were not designed to be continuously exposed to ethanol and items like gaskets and fuel lines could be degraded and weakened to the point of failure.  Also, ethanol is hygroscopic, meaning that it attracts water from the air.  Not as bad a problem if you have plastic gas tanks, but not good in steel tanks since the water sinks to the bottom of the tank and inevitably rust starts.  
Ethanol has also been rumoured to play a part in the dreaded gas tank leak in C6s, where the elbow at the top of the fuel pump cracks and gas leaks down the side of the tank.

Lucas Oil Safeguard Ethanol Fuel Conditioner is supposed to neutralize the effects of ethanol.  It’s available on Amazon and probably Canadian Tire.  You might consider using that in your older cars.