Yes..that is how the coil should be wired. + side is from the key switch. - side goes to the distributor.
The VERY most basic test would be to remove the wire from key to coil and scratch it to a place on the engine. With the key ON, it should spark as it is pulled across a ground.
If funds are not a concern, putting a new coil on will take it out of the mix!
Remember, the presence of that polarity reversing switch and the fact that someone removed its wiring required the distributor plate to be grounded. This had to be done by someone after the fact.
You said your engine has started and run fine many times before, right!
Stuart
