Theres no way I can tell sittin here whats going on either, so I will offer some comments which may or may not help.
Generally use of an elec switch, which replaces the points, isnt wired all that much differently. The IGN output on the IGN switch still (when on) must provide hot voltage to the coils input (NOT to distributor terminal)..........AND THERE MAY BE A BIAS OPERATING VOLTAGE SUPPLIED TO THE ELEC SWITCH which could also be fed off IGN switches output orrrrrrrrrrrr Could be fed off the coils input also............(same thing electrically, hot when IGN is ON).
Next, the coils output (to distributor) still needs a ground when points or elec switch is closed conducting current. That could be via a wire from coils output to the distributors side insulated pass through terminal (normal and same as if points) that wires to the elec switc "TO GROUND" wire.
If you have a wire TO AMMETER that would ALWAYS have hot battery voltage on it. If its to the LOAD (NOT battery SUPPLY) side of the ammeter, thats where the BAT terminal on a Voltage Regulator could wire or if converted to an Alternator, thats where the Alternators big main OUTPUT stud would wire.
A wire from THE SWITCH????? if its the IGN output switch terminal, that would be hot when ON and could connect to the coils input and possibly also to the bias operating voltage elec switch wire I CANT SAY FROM HERE.
If its a 3 wire Alternator, often a wire from coils input or IGN switch IGN output wires to the small side 1R Alternator Excitation terminal with a diode or rersistor in that line.
If changed to Neg ground the ammeter leads would need swapped or else it reads bass ackwards as well as the coil leads swapped so - goes to distributor.
Nuff said, thats all I can say sittin here unless I had better info