I'm slightly confused on my options here. I'd like to keep it original looking using a generator driven fan and I'm wondering if the belt will line up. I've been reading a bunch of posts and it sounds like it will, but I would like to know for sure, so I know which generator to take to get converted to 12V. Thanks
Your '39 Deluxe originally had a crankshaft mounted fan. If you want to have a generator mounted fan, you will need a two brush generator from a '39 Standard. They can be converted to 12 volt. The pulley will line up with the other pulleys on the 59AB engine.
If you have the space for a crank fan, as a 39 Deluxe should, I can’t think of any reason to do something different. Super simple.