Hi Don, 41 Code 42 Lugers used several types of magazines. Pistols in the O-Block were issued with E/122 and E/37 (fxo), both with aluminum bottoms. Further, there are two types of aluminum bottom fxo type magazines. They differ in the arrangement of the "P08" stamp on the side near the spine. Some later O-Block Lugers had the type with the "8" on "P08" closest to the bottom (the other type would have the "P" closest to the bottom and were issued later in the 1941 production).
As far as I am concerned, no information is available to me that indicates a black plastic bottom fxo type was issued with any 41 Code 42, O-Block Luger, or any 41 Code 42 for that matter.
There are E/655 armorers aluminum bottom magazines around, without serial numbers, but the E/655 "magazine" stamp went out with the end of the first third of the 1940 Code 42 production.
Hope this helps!!
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