Actually, they both have the same decals. One just hasn't been cleaned and probably has dried oil and/or smoke on it making it darker. There isn't much difference that I can tell from the pictures. According to the page it says the #2 has a more rounded pillar and arm than the #1.
Unfortunately, I have not seen any serial number lists for National. I bought a paw foot machine thinking it was older, found out that it was probably from early 1940s.
Janey - Neat people never make the exciting discoveries I do.