I will be very interested to see how much a set like that goes for. I have a Krieghoff Teck double rifle, built at the same time as this one, with interchangeable barrels in .458 WM, .375 H&H Magnum and 20 gauge/76mm, which I took to Africa three times. The .375 barrels are separated and adjustable like the double rifle barrels pictured. I didn't find this to be any particular advantage, and evidently neither did Krieghoff, since, as far as I know, they no longer make them.