"Uh, Chris, you are going to be using oil based polyurethane paint and clearcoat, so make sure that primer you applied is oil-based and not water-based." This is what I wish I could have told myself a week ago.
Starting anew on this paintjob (following my initial spraycan debacle months ago), I went over the bodywork again and again with Evercoat products. Took a lot of work/sanding/checking and rechecking 6 times over 10 different filled areas, but the it turned out well.
Then I followed up with the grey Primer as seen in photos previously.
Initially, I read through the write-ups on roll-on paint jobs and these said apply primer, so that's what I was looking to do. I went to the Hardware store and bought a Rustoleum Primer product thinking, "Rustoleum is good, can't go wrong with Rustoleum Primer, right?"
The Rustoleum primer I bought said it was appliable to metals, etc. And I wanted to get something on the Jeep over this hodge-podge of scratched black paint and evercoat that was its current shabby cover.
I thought it turned out well; I sanded out the orange peal and it looked like I was ready to thin/roll-on/sand multiple polyurethane topcoats. Well not so fast.
I find out the primer I used is Rustoleum's Painter's Touch -- a water-based latex. Its pretty obvious that you don't want to use this stuff under oil based paints like my Polyurethane. So, I have to strip the water based primer now and then redo the Jeep with an oil-based primer -- basically standard Rustoleum "Oil-Based" Professional Primer.
If any of you guys ever consider roll-painting/Spraying an old Jeep on the cheap using Rustoleum/Tremclad (Oil-Based) or Interlux-type PolyUrethanes (Oil-Based), don't make the mistake of using a water-based Primer!