I figured this one out on my own.  Manual was not too helpful.  CS C-130X Experience manual Vol. 1 makes written reference to "fuel" configuration in ACE utility when it does NOT appear there.  Only very limited write-up on this subject is in the C-130 manual vol 1. 

Here's how to make sure fuel tanks show up.  First, make sure Captain_Sim FSX C-130Experience "130" folder in the FSX base folder is opened, and the ACE utility for the C-130 in FSX is displayed.  Do NOT open the ACE utility yet.

Then  - 1)Start FSX.  Once you know FSX has started, 2) go back to ACE utility and start as usual.  Note there is an empty check box next to "Show fuel tanks" on right side of ACE screen.  Check this box.  Then, 3) remain in ACE utility and make the rest of your choices for your C-130, whatever mod it is.  At the last screen, hit the "SAVE" button and leave it at that - DO NOT shut down the ACE utility.  Let FSX load your aircraft.  Then choose the C-130 you want to fly and if you wanted external (drop) fuel tanks on the aircraft, they will be there.  NOTE:  To change the amount of fuel in each aircraft tank, you will have to use the FSX fuel menu as you would for any other FSX aircraft. 

Reckon CS staff figured this would save them having to include a fuel system setup in their ACE utility for FSX.  It works, but I wish they would explain it in very simple terms in the manual.

Yeah, well, it's the story of my life, I guess.  At any rate, this method works.  I tried it more than once the other way around (i.e., starting ACE first, then FSX) and it has consistently failed to work.

I find it interesting the fuel system diagram and ability to reapportion the amount of fuel in each tank in a chosen aircraft that is such an excellent part of the ACE utility in FS9, and is directly referenced in the FSX C-130Xperience Manual No. 1, is in fact not in the ACE utility for FSX as the manual states.  It's possible they may in future release an updated ACE utility for FSX that includes the fuel feature, but after all this time I'm betting on it staying like it is.

This seems to be the only hangup with what is otherwise an EXCELLENT product, fun to fly, not overly complex in its systems, yet quite realistic.  Having ridden in one years ago, including on the flight deck, I can testify to this.  The only thing I've done to mine is use a different sound set since, from personal experience, I don't hear an Alison turboprop in the FSX C-130.  It's a turboprop, all right, just can't figure out from where.  The P-3 and C-130 use the same engine - any P-3 sound set should give a user an accurate representation of the bird's real sound.  It's unmistakable.

Sorry, but it wouldn't have been me, as I only have Captain Sim products for FSX and P3D.