If I can find someone to chrome a crankshaft for me - what needs to be done to refit it to the case?
The actual process can vary a bit depending on whether it's a sleeve- or ball-bearing engine. One of the best is Bob Oge (Model Engine Specialists) on this link:
http://www.clspeed.com/parts.htm
SOP would be to turn or grind the crank OD undersize, then chrome and grind the OD back to desired spec. Since there's no center on the big end, and may not be a center on the threaded end, I'd have doubts as to the likelyhood of this being a good idea, esp. since you'd be looking at probably $100 plus to do the job. Looking for a used crank or parts engine would be a better plan. If it's a plain bearing engine, replacing the bushing is another possibility. Steve