The reason I mention sourcing parts is because I've been in that situation with a custom action.
Fortunately, the firing pin, spring and cocking piece were modified XP100 . With a bit of machine work, I was able to get the action back in service. 15 years later, it's still going strong.
There's a lot to be said for how the Kelbly's and others do their actions..designed around the 700 ignition pieces.
Good shootin' -Al
