I've seen several knives with that plain U S A on the tang! Is that a typical Kingston tang stamp??????
I wouldn't bet on it. Quite a few knife companies used the U.S.A. stamp on the tang, then either etched their name on the blade, or used an identifying shield, or made knives for special factory orders with no identifyers at all. There was a law on the books at one time that the country of origin had to be on the knife, but evidently it is no longer in effect, or just being ignored.
Members need to post good photos of their Kingstons for a decent survey to be done. Mr. Goins did not show any Kingston stamps in either his 1982 or 1998 editions. Sargent's 1986 book makes no mention of Kingston, and neither does Levine's 1985 (the newest I have). Searching the web has been fairly unproductive in finding examples, and most that I have found do not have clear representations of the stamps.
I would not just go out and buy every knife I saw with a "U.S.A." tang and call it a Kingston. These are just photosample representations used at the time the brochures were printed, likely 1947-59. Here is a composite of the stamps from the brochures and one photo I clipped.
I've only just begun researching the Kingston brand and marks, and so far, this is the best info to come to light. Perhaps Knifeaholic or someone else like LT will come here and show some examples and expound on Kingston. Meanwhile, I'll keep plugging on the research.
Codger