after more research...Locomotive 304 was the only locomotive I have found in any inside frame C class. Although it is a C17, the distance from the main driver to the cylinder is identical. I am to belive (however could be wrong) this would mean a similar main rod due to the same driver center, and same stroke.
This is mearly a thought, but could this rod have come from this loco??
Like I said, a long shot, but from my understanding it would be like the RGW to keep loco parts after the loco itself was scrapped....