But also give Briley a call. They have copied and repaired a couple of unique broken parts me over the years. If they still do that sort of work, they'll build a clone of whichever is the correct hammer. It won't be a Purdey repair, but it will be undetectable, and you will have it back in a fraction of the time and a lot less cost. On the other hand, by having Purdey do it, you will have a lovely receipt on their letterhead.