Personally, I would go for a used English rifle, but that's just me. Oh to be in your position!

Does it absolutely have to be a .470? Their association with Ruark, Hemingway and so many other 'names' pushes the value up. A .475 or .475 No 2, for example, would be ballistically identical to a .470 (in the real world) and may well be a good few thousand less. Try www.westleyrichards.co.uk