Due to the original key being made of “soft metal” or something. Or maybe it was the lock itself.
Looking at the key, it didn’t seem an insurmountable challenge for a talented locksmith, so I trundled off to Professional Locksmiths in Melbourne. First heard of them when I needed to get a copy of an unusual work key. Which they were able to copy.
“Yes, we can copy that. It’s going to cost $11 for the key blank. We can do it now for you.”
Five minutes later, I was out of there with my newly copied key.