Yeah, those unusual WM.23 configurations are totally fictional. You see, I am the illustrator of the last several WM.23 drawings that Justo posted (I had sent them to him a few years ago for him to use as he wished. Guess he merely forgot who they were from and that's OK). The WM.23 with the Daimler-Benz engine was, according to the sources I had available to me at the time, considered but never really "designed". The 2-seat reconnaissance variant was designed at the same time as the single-seat fighter, but was never considered for production. I do believe that Weiss-Manfred (Manfred-Weiss according to some sources) was considering a German radial for the planned production model (memory wants me to say the BMW-801, but I don't think that that would have been available).
It would be interesting to see what the WM.23 would have been like with a BMW-801, though. Now just let me find the CADD files...
Anyway, all the other "designs" were just my imagination working overtime, as it is wont to do with interesting airplanes.
The Hungarians only built ONE WM.23 and that one crashed sometime during the flight test phase.
On another note, while some sources designated the Daimler-Benz version as the WM.123, other, more reliable Hungarian sources, state that this variant was probably designated as the WM.22 (or maybe the WM.24? Please correct me if I am wrong).
Last note for Justo: Please my friend, don't think I am accusing you of plagiarism or stealing my drawings. I know you to be an honorable and trustworthy man, and THE BEST DAMNED ILLUSTRATOR I HAVE EVER SEEN!! I may not have put my name of the drawings when I gave them to you. My apologies.