sooguy:
I went home & checked my mags.
Just after the 94 "assualt weapon" ban, Colt marked their magazine w/ a manufacturers' code & date stamp on the lower portion of the magazine. (As pictured) This code of 33710 is the same as Circle Kay / Okay. Which makes sense as Okay manufactured Colt magazines. The only difference being who was listed as the manufacturer on the floor plate.
Of all my Colt magazines, the earliest showing of the "Military, LE, Goverment, Export" only markings on the top 1/4 of the magazine bega in 1995.
From the picture you show, your mags are blocked by a rivet. What capacity are they limited to? I only ask, because if it is possible for you to send your magazines back to the US of A, and receive capacity specific magazine, such as 5, 10, or 15 round, maybe that'll work out to the best for all?
I must add, Ryno_the_wyno's post leaves me a bit baffled. From my own experience, the early banned Mil/Gov/LE/Export only magazine showed the MFG# + the date stamp, such as as any date after 09/04. Then in at least 1995 the magazines exhibited the "restricted" nomenclature on the top 1/4 of the magzine . This wording was on one side of the magazine, on the other was the "Colt's MFG". While I admit, there was no Colt "logo" on the magazine body itself, but the magazine did display "Colt MFG" &/or "Okay". (Logos & brand names being seperate, of course)
HTH-
Sly