why does this car not charge and contunue cranking after the key is off?

The Starte solenoid is either Stuck closed(welded itself) or the ignition switch is screwed.

Since it will not start without ignition being activated at least the starting circuit is working properly. You obviously have 12 volts present at your distributor/coil as soon as power is available which could be a simple short circuit or an ignition module. If it is a short, try pulling all accessory fuses and see if that can help isolate the source. My guess it's the ignition switch (not the lockset).

you switched a wire or two in the back of the solenoid. you should have three wires that go to it, or even three given the age but wires are biased by the size of the terminal ends. you should have the battery cable coming down to the large terminal on the solenoid, a second wire to that same terminal that should integrate the charge back wire to that same post and then the starter control wire from the ignition switch. if you switched the two small gauge wires, you would end up in your situation.

Sounds like its dieseling which means that the left over fuel is burning in the combustion chamber without spark

and as long as the battery is connected the fuel pump is still pumpin etc

You've either got your wires to the starter crossed with the ignition wires or a wire touching the post on your solonoid to your main terminal on the starter, basically, check your wires