The top turret is indeed supposed to rotate, it has ball-indent set on a stiff spring to hold it in station of each hole for dies.
You'res like a lot of these old presses needs to unassembled and cleaned with a good solvent, probably some rust in different places like the top nut and the side hex-screws.
Be advised there are hex-screws holding turret in place, you may have to loosen them up with some WD-40 or other rust remover. The hex-screws hold the turret in correct die alingment with the shellholder.
Just unassemble and clean thoroughly, then reassemble and enjoy loading. I've owned 3 or 4 of these presses...but now only have one.
Jim