Hello. I know what you mean, but so long as there is no "LEO Only" or similar marking to indicate to you that it's post ban, you're in no trouble. With Hi Powers, there are reportedly tons of unused magazines made before the cut off date from many foreign sources that do or did use the Hi Power. Essentially,these are new even though made several years ago before Sept 13th, '94. Should someone be making post-ban magazines w/o the marking and selling them as pre-ban, they could be in trouble.
Best.