From a junk yard engineering point of view:
Start with a surplus gear reduction motor, small pulley.
Belt to 24 inch pulley from junk air handler fan or back of commercial front loading washer on counter shaft.
Belt or chain from small pulley on other end of counter shaft to 48" bull wheel.
Sizes to be determined by amount of gear reduction.
1750 / 25 : 1 gear motor = 70 rpm.
6" pulley to 24" pulley = 17.5 rpm.
6" pulley to 48" pulley = 2.1875 rpm.
Ten times too fast, rockinghorsepoop!
Higher gear reduction on motor, 4" pulleys instead of 6", 3 phase motor & VFD. VFD would be nice, slow ramp up and down, and variable speed.
That is a "fun" one, good luck on the solution.
It would be nice to see a paint line drive system. I photographed one years ago for a client. Saw another in a Westinghouse plant near here. Slaughter houses and auto assembly lines use the same type of system.
Paul