Those EAA Competition Mags may be the older (Late 80's/Early 90's) vintage Competition magazines that are very rare and hard to come by, unless they are making them again, which is doubtful, as your magazines have the older Black Follower, and the newer magazines have a Red Follower.
That rounded bottom came in a variety of colors. If vintage and you paid less than $70 each for those vintage magazines, you got a deal!