Get it in writing from the Volvo rep. guaranteeing the seal longevity.
An option would be to have the area hard chromed. It's not
cheap, but probably cheaper than
buying a part from Volvo. The surface is polished down a few thousands and then hard chromed back to standard size(different material than polished chrome) to produce a very hard, long lasting surface that will probably outlive the engine/drive.
It's a common practice on
equipment used in corrosive environments and to
rebuild crankshaft bearing surfaces.