I like this older thread a lot. I'm glad others are not constrained by reality and run non prototypical trains. On the Pennsy part of my layout there is a visiting Arnold #2468 Crocodile that pulls a small string of European rail coaches as an excursion train. Love to watch the connecting rods on all the drive wheels work as it quietly goes about it's business. Really does not look all that out of place along side the GG-1's under the catenary.
I checked the Fleischmann website and found a link to order replacement parts: http://www.fleischmann.de/en/service/spareparts/index.html Maybe it works. Parts diagrams can be found in the web, too, see here http://www.mtkb.de/Umbau/Decoder.htm "Waschzettel" is normally the care label in garments, but here used as a synonym for operating instructions.
Hey, we have part numbers.... so far so good..... http://www.mtkb.de/Firmen_PDF/Waschzett/fleischmann/7030_br91/fl7030_br91.htm