Over here in Oz one such item is marketed as "SpeedySleeve" and probably hails from USA anyway. It's a thin one-piece sleeve which is heated slightly to fit over seal wear marks on cranks etc. Usually used to negate the need for an engine strip down in places like front and rear main seals. I've used them on Toyota 4X4s using a new original size oilseal. Another trick is to fit a new seal and, if it's possible in the appplication, either leave the seal a few mm short of fully seated or else push it further in so the seal runs on an undamaged part of the journal. If the engine is apart then I'd get it fixed properly, although this may be expensive on a nitrided crank ?