There are score marks on the cylinder walls.----Pistons are likely scored as well.----This motor can / will run.-----But it should be taken apart for proper repairs.----Little bit of carbon on pistons is normal and causes no harm.
Have the battery load tested.----Often a free service.----Then take a 12" jumper wire from battery post on solenoid to small terminal ( not the ground ) on the solenoid.----Report exactly what happens.
????---The key switch applies 12 volts to the solenoid.----The other small terminal off the solenoid goes to ground.----The solenoid connects battery to the starter.----This should be so easy to trouble shoot !