I, too, have a nagging desire to know where my purchases are originally sourced. . Like other things in life, we may never know !
Ed may not tell you the source of every kit he sells, but if it is Dayacom I am quite sure he will tell you. . Vendors do have their secrets too !
It would not surprise me if several US vendors have found a way to do "group buys" wholesale from Dayacom and/or other sources. . It that case, there may be a reason to not disclose the source even if it is Dayacom.
I think it is common knowledge, and I think it is true to say, that PSI designs all of their own products, and shops around for an appropriate manufacturer. . I believe they have operated in this "independent" manner since the inception of PSI. . Some of their products are copied by others but it is rare (if it ever happens) for those copied products to be available on the open market in the USA.
I can think of one such copied product, the PSI 30 Caliber Bolt Action pen kit, which I have seen in more than one copied version, but the copies are usually distinguished by being noticeably inferior to the PSI kit in one way or another. . Never have I seen such copies available from a US vendor, but then I don't know ever US vendor and I buy from only a few of them.
Now, if we briefly change the subject, but continue on the topic of copied products, I have seen copies of the Zen pen kit being sold on the open market in the USA. . I can't remember who the original designer/vendor of the Zen kit is but the copies are/were definitely of inferior quality. . I know that CSUSA sells the "original" Zen, and it seems to me that the source is Dayacom, but there may have been a name change.
EDIT: (again, we were typing simultaneously) . Please note my erroneous reference to the William Wood-write Napoleon pen kit. . It is NOT the same as the Dayacom Jr. Major that you pictured above. . There is, however, something along this line residing in my neural cortex from years gone by. . I have deleted my statement from my post but that statement still survives in your quote of me !!! . If you would care to do so, you could delete that sentence in your quote, please.
FURTHER EDIT: On further reflection, I believe I should have used the name Helix, instead of Napoleon, as being a renamed version of the Dayacom Jr. Marshall (not Jr. Major). . The Helix is no longer being sold by the Canadian vendor that I mentioned. FWIW, the Helix gets discussed in this IAP thread:
http://www.penturners.org/forum/f18/helix-kits-123014/