Hi Bert, you're right! This is Praga RV (sorry, not RN) and nothing else. Thanks for that, the thing was moved immediately from "Unknown" to "Praga" folder. BTW, judging from your nick your interests aren't much differnet than mine!
Bill, sorry I forgot to tell you this earlier. Yes, I think all those strange rail vehicles of Allied origin will fit here. My point is they are weird too and deserve to find place in this thread. Also, another good reason for this could be I'm not aware of any Allied vehicle that wasn't captured and used by Germans, on rails or not.
Another pic of the strange thingie posted little above by Bill (or I think it is the same):
Could it be Krupp L2H43/143 based?
And here is a true rail classics:
Cheers!
"...and on the 8th day He made truck so that man, made on 7th day, had shelter when woman threw him out for the night."