In answer to my own question and even more research, I came across this which is what I wanted to know!:
"The cadeca in terminal #2 is in departures, not arrivals. After clearing customs, upon exiting the building at the arrival section, go right about 75 meters still under the canopy to the entrance to departures. Enter departures and you see the check in counters right in front of you. Instead, take an immediate right down the hallway. The cadeca is about 30 meters down that hallway on the right hand side. At least it was that way when I last came through terminal #2 about a year and a half ago.
Note: upon exiting arrivals with CUC in hand, there is an open air beer stand immediately to the right. No better place to spend your first CUC in Cuba than on a cold Cristal or Bucanero."
So even tho the person who posted it travelled about 2 years ago now, I'm hoping it is still correct! Particularly like his advice on how and where to spend that first CUC!!