Dominic,
Under Edit: Yes, check to see if you have 12 volts at the coil with the starter cranking. And Harry has a work around to bypass that part of the ignition switch if it is bad.
So you have 12 volts at the + side of the coil with the key in the Run and the Cranking (Starting) positions? If so, all that is left is the Coil, Breaker Points, Condenser, Spark Plug and the wires.
How are you testing to find "no spark"?
Can you check for continuity between:
1. coil and breaker points
2. breaker points and ground (better yet neg (-) battery)
3. breaker points and condenser
4. condenser and ground
5. coil to spark plug wire