Trex,
You mentioned the Rifle was from the Winchester Custom Shop, do you know which custom it is?
The Custom Safari Express (retails for $3043.00) is offered in .470 Capstick currently and was first produced in that chambering in 2001.
The Custom African Express(retails for $4572.00) was chambered in .470 Capstick in 1999 and 2000 only. I ordered a Custom African Express in 1999 when first announced and it took 10 months to get the gun done. The gun is truely art and I was told that there were less than a dozen African Express' made in .470. By the way-- the African Express was offered in either stainless or blued versions-- I have seen 1 other African Express in .470 - it was stainless. Mine is the only blued version I have ever seen.