All, good ideas! I'll continue my search...
Ref: original post, here's photo examples of an excellent Toy Story PF mod but unfortunately it lacks a parts list which in turn would make ordering the right pieces for the mod much easier.
Another example is this Caboose for Emerald Night (sorry not trying to turn this into train tech, just my favorite theme), but again without even just a parts list makes it quite difficult to reverse engineer or source the parts.
As for instructions, true about copyright, but I was thinking more just the instructions to build the enhancement portion.
One of the reasons I ask if something like this exists; I have thought of making a blog of unofficial set mods for people like me wanting to do them. Anyone with an opinion on that, would you like/dislike/contribute mods??
Thanks,
KP