Lonestar --
That's an excellent question; actually one I'm dying to know more about myself.
According to the more reputable SN sources, the first 2N was a 1942 with SN 9N99003. Seems straightforward enough until you note that same sources say the last 9N was a 194
3 with a SN of 9N105412
I'd say you have one of the very last 1942 9Ns but I can't prove it like I'd like to be able to. I'd love to know the real deal of whether Ford did a clean conversion from 9N to 2N in which case several SN guides are glaringly wrong. Trouble is that few folks tend to be concerned with these details -- frustrating!!
Let me know if you discover anything,
Pete P.
Harborcreek, Penna.