I am assuming that on your 59AB engine that your alternator is mounted in the same position as the original generator on that engine. If so, the cooling fan does not attach to the alternator but is mounted on its own seperate bracket attached in front of the bracket for the generator/alternator as shown in these illustrations.
So, what you would need to mount the fan as it was originally on that engine is two pulleys on the end of your crankshaft, one for the belt around the water pumps and the alternator, and one in front of that for the fan. Then you just need the fan bracket with fan attached.
Here is the entire mechanism that you need for sale on ebay:
http://www.ebay.com/itm/42-46-47-48-...item1c1f6e5d04
If this doesn't answer your question let us know.