Kevin,
That hammer looks like it has already been stretched out a bit to contact the nipple better.
Do you have a photo of the lock in place on the rifle? That would tell the story a bit better if you did.
It looks like you have a short T/C nipple on the rifle, yes?
Sometime you have to opt for function over appearance. So maybe the original hammer would do the job better.
Or you could just grind the end of your preferred hammer cup so it would contact the cap and be done with the project.
Do you know how the rifle shoots? If well, then go for it. If not, there is always eBay.
John
PS: Was low to mid 60's today with fairly low fog as I sat on the T- Pier listening to our community band playing its August concert. Mid 90's up there, eh? I don't envy you a bit. But it was pretty nice when we were there in June. I really enjoyed our time at the RDV.