Martin - anything from FMS can be converted to a Kex (RF's visual model); the process isn't perfectly straightfoward, but I'm working to simplify it. The resulting file will NOT have moving parts (unless they're fixed in 3D Studio), but it is possible to import .x files to several different 3D programs.
If you can get the original author's permission (or if there's a ReadMe in the file that says you can re-post it,) I'd be happy to convert the models to KEX files. From there, you (or anyone else) can do the work of mapping the physics parts.
In the meantime, watch the Dragon 4 thread. Now that we have permission to use the model, we'll be going through the conversion process there. I'll post some notes as I go.