Call Barbie first, but my experience with her is that she just asked me to send her the customer's old broken tumbler, along with a note saying which of their locks it was from, and then she sent me a new tumbler for free. She paid return shipping.
Tumbler she sent was already drilled and tapped and hardened. With the one I received the threads were a bit too shallow (not threaded deep enough), so it needed a little work. Also needed polishing. I think the best way to deal with that is to anneal it, then finish the way you want, and then harden it again as you would a new one.