using the key is to remove the lock cylinder from the switch body, taking the switch off the dash requires removing the retainer,
maybe screws like a 54? that tech tip was written by a 37 owner
sounds like the switch you got is
a 'generic' type, as Tim says, you'll need to use an ohmmeter to figure what each terminal does, if there's a center pin that should be the battery +, if the switch has a spring loaded position there will be an unused terminal for that 'key start' function, another will be ignition when on and the other may be an accessory power terminal - ignition and accessory should be interchangeable and only show continuity when the key is on
Bill