Headspace is adjustable in either direction (shorter or longer) by the barrel threads. There is a limit that depends on the chamber cut in the barrel to be correct not to leave too much of the case head unsupported, but for the few thousandths, we are talking about, unless he sees an expanded place beyond what a normal pressure ring on the case is like, it should not be a problem to do.
Factory repairs can be quick or slow. If a replacement part is needed and they are out of stock, they have to wait for the next scheduled run of the product to have any available.