Engine number will be stamped on the flange behind the starter. Someone may have fitted an earlier engine to a Super.
Has the tractor got a dash panel under the steering wheel or in front of the gear sticks? Has it got disc brakes?
Throttle through the block went out in 1957 on tractors, although I have seen replacement blocks with it, these were for petrol trucks not tractors and are rare.
When we fitted new blocks to early tractors, in the dealership, we used a Ford adapter kit that bolted on to the rear of the block and took the linkage around the back as per the later FMD, Power Major and early Super with vacuum governors.