FWIW: From years of experience, repeating the same humble opinion mentioned before used by thousands of vintage mechanics with thousands vintage engines:
When an intermittent, difficult to find, "No Start Problem", occurs, immediately after an engine would die & definitely "not" re-start did you try:
a. Turn ignition switch OFF, pull out choke, allow engine to turn about 12-15 revolutions, & "immediately" remove spark plugs to "see" plugs are wet w/gas; hence, when wet, usually it is not a fuel problem; however, if plugs are dry, it is usually a fuel starvation problem.
b. Next leave plugs out laying on sides, turn switch ON -- rotate engine & check plugs for fire; if no intense spark, usually an ignition problem; however, if one sees good spark, usually not electrical problem.
The above can usually quickly diagnose either an electrical or a fuel problem & in many cases it can cut your crying time in half & Kleenex Tissue use & Charmin tissue use in half.
Also, it usually saves valuable time & can cut your thousands of parts changing in half.
Just sincerely hope this can help. Also can help ecological paper shortage.