I think the general concensus would be that re-boring is only an option if the original barrel is crucial to the function/value/appearance of the firearm. Examples would be unique barrel profile or hex-section which could not be easily replicated, front claw-mount on the barrel, makers engraving or unique proof-marks, exquisite full-length rib or quarter-rib, or some other aspect of historical significance.

If none of these apply, and they are unlikely to in the case of a Ruger No.1, then rebarrelling would be the cheapest, simplest, and most accurate option. (..in Australia at least!)