In reply to d508934:
Our local locksmith (3rd generation same family) is completely disparaging about "locksmiths" who have to resort to drilling. He's opened a 5-lever Chubb mortise lock for us, no problem, and for other people we know. He's got into a neighbour's safe without wrecking it, too.
He says that there's hardly ever a need to drill a lock and that a lot of so-called locksmiths are just "drill cowboys" with no real locksmithing skills who quickly resort to drilling and charge a bundle for it.
He also carries a stock of hand-made springs (that he makes himself) for Victorian internal door locks...brilliant. I've renovated about 6 of our non-functioning internal locks with them.
And he's actually cheaper than a lot of the "cowboys" around.