Hi Jose,
I know a bit about labels we believe made by Barrett/National. There have been a couple online discussions of that sort before. I have strong observational evidence that Montgomery Ward's early Gold Bond pens and Sears's (yeah, the "s's", probably is correct) Diamond Medal pens were made by Barrett.
There has been a tendency to treat National as the main label, akin to Sheaffer being the maker of Sheaffer, WASP, Vacuum-Fil, Craig, etc. , the difference being that a tiny minority of "National" pens are marked National, unlike the Big-5 pens, whose majority of pens are imprinted with the company name.
As I wrote in my Gold Bond articles last year:
America's Big Five pen manufacturers from the 1930's included Parker, Sheaffer, Waterman, Wahl-Eversharp, and Conklin. All five manufacturers also sold generally less expensive off-label pens, pens which generally carried no markings tying them directly to their respective makers. While some clearly were lower quality products, the best appear to have had manufacturing specs similar to their main-brand equivalents. Another company of significance in play for the off-label market was National, with its somewhat unusual business model, issuing most of its pens as “brands” not its own, thus falling somewhat under today's collectors' radar relative to the Big Five, who had trumpeted their own labels far more mightily. National sold nearly everything off-label, its pens often branded/rebranded for sale by catalogue shops and by brick-and-morter store chains.
In fact, while the hobby (if I might generalize) tends to assume that National was the core entity, it is not clear to me that this was so. Information about National/Barrett is sparse.
In fact it is possible that National was just one more label for Barrett. Evidence-- subject to overreading/misinterpretation-- points both ways.
In my article about Wahl's Equi-Poised for the first issue of Paul Erano's Fountain Pen Journal (I recommend subscription), I offered a snippet of the lawsuits that Sheaffer pursued against Featherweight and Eagle. Notice who backed off from copying Sheaffer's Balance in the face of the Cease and Desist letters:
The Wahl company was warned. Presumably had it been necessary, the "Parker Pen Company", "LE Waterman", "Chilton" would have been warned too. But, "National" was not warned. Instead, the CE Barrett company was warned.
There is evidence pointing oppositely too, that labels made by CE Barrett (eg. Gold Medal) fell under a National umbrella. But, that is a tale for another day.
I would enjoy working again on a list (publicly, here) of labels made by Barrett. FPN had something like that a few years back.
The Barrett/National structure still is but weakly explored.
regards
d