Yes, your assumptions are correct. .010" = .25mm . This just means that you need to get the bearings for rods and mains in that size rather than standard. You may also have to have your machinists cut the thrust surface of the crankshaft to give correct thrust tolerance. Most oversized bearings have a built up thrust surface. I have built many n/a engines with no issues with running a crank that has been turned 10/10.