The ballast is right in that cylindrical can behind the reflector on each flood. The remote ballast encased in tar makes the ballast last much longer too. Typically all the guts are crammed into an undersized flood light housing and cook to death in a fear years.
Another reason these tend to have more vintage lamps is because these things are a PITA to relamp so they probably don't bother until the lamp bites the dust completely lol.
Never thought about that, but yeah totally makes sense!
@Mike:
Yep once GullWhiz mentioned they were remote ballasted, I figured that 'can' had to be the ballast