Jan, I have S/42 1938, serial # 3438m (SE83 SE63 MTP) All matching except Mag: 1448m, SE83.
Dana, I assume you have the gun that belongs with those mags? I have been compiling data on guns with single and double matched mags from auction sites, dealers, the forum etc. A lot of the double matches are ground and re-numbered or altered either one or both to make the pairs. One dealer in particular is responsible for a large number of these. Your mags and the other two pairs in this thread are all good looking legitimate examples. You are also correct, David's mags are DE/63 mags the L/H side of the "8" is flat and the ball of the 6 is touching the loop on the right. JBI agree in your photo the stamps on the pistol look like eights. On the mags however, to me they look kinda like sixes.
The stamps on my '38 mags more plainly sixes. Interesting that they changed the fonts.