My Jeep started having problems very similar to the ones described here. I changed spark plugs and cables, the cap and rotor, the ignition coil, and the starter, but kept having problems. Today I searched the internet for answers. I thought it was something major, or electrical, and I almost gave up. When I read this post, I had my doubts.
I was about to take it to a mechanic, but it would not start, so I figured I had nothing to lose. I found the box but could not take out the reservoir since I only had channel locks with me. I loosened the only screw I can access, and "voila" it started right up. (knock on wood) It is running great.
If I knew where you are, I would send you a nice bottle of Whiskey.
You are a hero for spending the time to trouble shoot the problem, but more importantly, for sharing it with the rest of us.
May God bless you and your loved you these coming years.