I received an e-mail from an Sn3 modeler in the U.K. who needs the exploded diagram for Rio Grande Models kit #3317-D4, a D4 Tractor in S scale; it accompanied the full instruction sheet. He already asked the new owner of Rio Grande Models, Craig Tribuzi, but it was a dead end.
If anyone can help, please reply here or e-mail me directly and I'll forward the information or drawing.
Russ