Thanks Björn
I presume no STKZ is mentioned in your document?
Does the document actually say that WNr 240-0019 and -0020 were built?
There seems to be quite some uncertainty about that.
There were also black out WNr among these 20 numbers.
240-0007 is reported to have become 240-0009 and 240-0008 is said to have become 240-0010.
It would be interesting to know why basically all authors so far have chose to disagree. Quite possible various documents located send out contradictory signals....
Cheers
Stig