Unless people have the ability to home machine specialized chips, sensors and circuit boards we're going to be a lot worse off than Cuba. It's a lot easier to home build a float chamber or choke lever for a '50s vintage carbeurator than it is to crank out an electromagnetic solenoid valve for a modern fuel injection system.
Just go old school. Convert them to crank triggers with carbs or throttle body injection and throw away the computers and injectors. Easy to do with minimal knowledge and tools....
Fuel, spark and compression and it will run. I have run lawnmower engines off a shop rag in the intake that was soaking up gas by capillary/vapor action from a beer can...