Inconsistent spark plug firing; can't get all 4 to fire

[Todojo]

Hi, this is my first post here, as I wasn't able to find a thread on point.

I'm trying to resurrect our 1931 deluxe roadster bequeathed to me by my great grandpa. Recently while doing another test drive around the neighborhood it sputtered and lost power. We finally found that not all of the points were firing after installing a translucent distributor cap. What would cause two or three sparks to fire while the remaining don't? We moved the spark plugs around so it's definitely not the spark plugs. It seems to be something in the distributor because if we apply pressure to one side of the distributor pushing down it ignites more than one contact point but we can't get it on all four. Temporarily, to produce the same pressure, I pushed a small wedge of wood under one side of the distributor which helps it consistently have three sparks but the number two spark plug still won't fire. I even took apart the distributor looking for any issue but couldn't find anything. I have never taken the distributor off the head, however. We have a modern condenser installed.

I'm also curious how the spring end of the armored ignition cable is supposed to make contact with the lower plate of the distributor. I noticed that spring isn't very "springy" and found mention of it needing to make good contact but not too much otherwise it will ground out. I don't understand what that means or if it relates to my issue.

Any thoughts would be greatly appreciated. Thanks!