I'm pretty sure that wire going into the top of the black block is the primary hot from the transformer. Trace it back to be sure. The remaining holder in the block is most likely a fuse holder. If this is correct, the five red wires with the black stripe are the "hot" wires that should go out to each bay. That's why there would be fuses on them. That wire doesn't connect to the motor starter. The wire that connects to A1 that you show in your picture above should come directly from the rotary switch from wires that are jumpered to the same positions as
soap, rinse, and wax, but from the second stack. I can see in the photo that there are two wires connected to the A2 terminal on the contactor, which would be the "common" wires, which is correct. I was mistaken about the thermal overload, yours has separate thermal overloads above the contactor that break the power to the motors. The motor starter
may run through that, I can't tell, but you should be able to trace it through if it does. It's possible the main "hot" to the bays goes through it, which would be best because if the thermal overload trips, it will also break the control voltage to the bay and keep a customer from losing money. I would rewire it that way if it's not already like that.