Re: no spark,. stator ,mercury switch
Now that you have spark on ALL spark plug wires you need to ensure that the distributor is indexed to the crank flywheel so that each spark is at the right cyl close to the right TIME.
Look at the top of the distributor pulley, find the curved line, across the top, rotate the flywheel to TDC and see if that curved line matches the curve of the outside of the flywheel.
Next, use a timing light attached to the top cyl (#1) REMOVE ALL SPARK PLUGS and ground them so the motor cannot start. Disconnect the throttle cable and wire the throttle arm wide open so that timing is fully advanced.
Crank and check WOT Timing.
Reinstall plugs, reconnect throttle cable and start.
Remember, the stacked 6's like fuel and often need LOTS of choke before lighting off.