Thomas, I'm glad we could exchange so much about the long process of developing a second version of your stunning crocodile aswell your development of the 8-wide versions of some my cars :-) They are so advanced I'm thinking about rebuilding mine
If you're interested in some of their little 7-wide R40 compatible idols, you could have a look into my flickr album :-)
As Thomas already stated, his sophisticated wheel arrangement unfortunately can't be compatible to R40 curves. But I altered the design in my adaption of his crocodile so it actually can run on R40 curves (with some visual drawbacks like hovering flangeless wheels Thomas wanted to avoid)! I don't want to hijack this thread, so I won't post pictures here, but I have a flickr album with the dark green SBB BE 6/8 13254.