Hi Dave: Let me hit the files. I have two three drawer lateral files in the garage with a lot of this stuff and it's going to take a while to find the original document.I have never seen any mention of effort by the railroads to deal directly with the runners. In the latter part of the war, the government controlled the shipment of cotton so closely that it was hard for roads to get cotton to the ports, though a few did.
Someone had to buy the rails and ship them. I doubt any runner company was willing to certify the quality of the rails and handle all the work necessary to ship them, unless they had a contract for the work. Much easier to load various high-value items or government freight.
Maj. John M. Robinson bought supplies for several Virginia RRs in 1863 while also buying material for the Confederate Engineer Bureau. He though he was going to be kept in England to continue to buy for the railroads, but that did not happen.
What can you tell me about this 200 tons of iron in Bermuda. Was it RR rail or armor? Can you provide references?