Ed, most of my EO knives have been sharpened a few times so i can't judge original blade shape from these.
The 3 at the right as you look at my pic. have this more curved belly, best example being the top one.
The 4-line Camillus EO Jacks have at bit more of a full belly than the Imperials.
If the blade on yours is the same profile as when it left the factory, then some of my re-sharpened ones may not have as much blade loss as i had thought. This is the reason i posted my observation about yours. Unused or at least unsharpened ones are rare so your knife is important in showing that this straighter blade edge is how some of them were made.
I use my 9X loupe to examine blade edges to look for evidence of re-sharpening. If the blade is also unused or just very lightly used, the striations (perpendicular to the long axis of the blade) from the factory belt sander can be seen along the entire edge, both sides, as these were not highly polished edges (i.e., same as most production knives).
roland