1976 16HP Briggs & Stratton single cylinder engine weak spark

I have a 1976 Briggs & Stratton single cylinder engine on a Gravely 816s lawn tractor.  Everything is in good condition except it sat for 6-7 years in a shed.  Engine code: 326437-0170-01  7611161 _ . "0170" may be "0771" as it is difficult to read and I cannot find 0170 but I can find 0771 engine code.  I tested the ignition switch in all positions, tested the starter relay, replaced the starter, magneto, and condensor (all from Jacks!!).  I tested the kill switch and tried with the kill switch removed from the circuit.  I cleaned the points.  Originally, I got no spark.  I replaced the magneto as it tested bad on the bench (Jacks was great about this).  Gapped the magneto via 0.business card.  Flywheel magnets are strong enough to hold a 1/2" ratchet.  Now I get a weak spark ONLY when I hold the spark plug lead next to an engine ground, approx 1/16" away.  No spark at all at any further distance.  I checked the points cam and that seems to operate correctly, gapped the points. Still only a weak spark.  Any ideas?
 
With the magneto mounted in place, when I test for continuity between the kill switch lead from the magneto (disconnected from the kill switch lead from the ignition switch and the condensor lead) and the engine block, I get continuity.  Is this correct?   Could voltage be draining through the grounded magneto?
 
There is only 1 safety switch - for the clutch.  Since I am getting the starter to turn and a weak spark, I concluded the safety switch was not preventing it from sparking.
 
This engine also has a separate coil under the flywheel with 2 leads - one goes the the battery side of the starter relay and the other goes to the lights (which are long gone but the switch is there).  I doubt this has anything to do with the weak spark but figured I'd tell as much as I know.  
Help!  Winter's coming!