Door Mirror Ducato

Ours is a Ducato coach built motor home the year before the new model with the upswept headlights. The 2 metal brackets holding the offside mirror part to the solid arm have broken at the mirror end.and the only mirrors we can find have 2 arms. Will this fit our arm which is one single block. I hope someone can help as we don't want to buy the wrong. We would like to buy off a scrap vehicle can anyone tell us where to buy. Thanks.