I have a D&H that came with my BCM, has a BCM plate, and the cage code appears to be (letter) O4tQ4, or maybe (number)04tq4. I bought 14 more mags today with PSA plates, and the cage code appears to be the same, BUT when I was searching around on the internet for the D&H cage code I found multiple major websites (including PSA) who said their D&H mags are cage code Q4TQ4.
Also, two of the 15 D&H's that I now own have one style of imprint (I guess you could call it a font), and the other 13 have a different font. As far as finish and function, there doesn't seem to be a difference.
Any other D&H mag owners want to weigh in on this?
Barstow