anyway, I would ask you to forget my previous post:
Although the Lima wagon is also representing an UIC standard type with 18,50m loading area and 19,90m between buffers, I think I have a better suggestion.
The Fleischmann 5287 Res type flatbed is easy to get, it has the same dimensions, the distance between the stakes also seems to be correct, the side walls can easily be removed, the frontal walls need a little modification at the upper corners, the short stakes (which at the original hold the side walls) must be cut off, the plates below the platform must be cut smaller, and finally some details must be added, especially the hand brake wheels and one step.
Unfortunately I don't have own photos of this wagon, but you may see here:
http://www.gebrauchtemodellbahn.de/Spur-H0-DC/Wagen/Gueterwagen/Fleischmann-5287-5706-Rungenwagen-beladen-der-DB.htmlRegards
Stefan