Would replacing the hands during service look wrong if they were not of the same vintage as the dial? And I guess if they replaced the dial also with a Tiffany stamped dial it would be of current production if it would fit. So I guess it's better leave it...
replacing hands isn't a huge deal, but depending on level of patina it can look odd. My example in particular seems to have the original hands (from what I can tell and the opinion of some knowledgeable folks) and it looks right. But replaced hands aren't...