I'm not aware of any widespread issues with it. Its just that the electric choke was added to the ignition circuit and the ignition circuit is not fused.
If the other items in the ignition circuit shorted, that too would have killed power. But that one is near the carb.
see if there additional clues - like if the conductor touched ground, the copper should show spot damage from the amperage.

I agree its worth looking for damage all along the path.
I'm not that familiar with the '73 choke assists, but I'd want to check that the short wasn't internal.
The other thing to check is the fusible link. While there is not fuse on the circuit, the fusible link could have melted.
If the fusible link is melted, then definately check the other terminal connections.
http://www.heritech.org/cuda/Charge2.html

edit: Service manual shows the choke and choke control wires to be 18 ga, far less than the fusible link. So they should have melted before the fusible link.