[red-star25]

There seems to be more overlapping WNr..
There are Bf 109 D-1 produced by Arado Warnemünde and E- from Messerschmitt sharing the same range around 25xx.
In some of the repair documents, available in Freiburg, are several Bf 109 D-1 mentioned with the prefix 2/.
In the W 34 production is another block with overlapping WNr. in the 1000 region.
ATG has here W 34 hi (up to 1030) and B&V W 34 hau (up to 1012)
So far I did not found any evidence, that here a prefix was used too.
Some of the B&V docs used instead the letter H- in front of the c/n.
like H-1006, H-1008, H-1012.
The He 50 seems to cover the range 2/951 up to 2/964.
The use of prefix 3/ seems a little bit without any system.
I have here 12 reports about Fw 44, Go 145, He 72, Ar 66 W 33, W 34 and Fw 56, where it looks more like typos in the docs.
One doc from Henschel mentioned a bunch of Hs 123 repaired, with the prefix 1/ used.
So there is still some research needed, to get a better overview about the system used in the late 30´s.
Regards
Dirk