Perhaps an original lock with a stylized hammer?
That's what I plan but (having bench-made several hammers in the past for British shotguns, rueful grin, LOTTA work) I'd really rather find a damaged original hammer to use as a donor.
BTW I really, REALLY, like the shape of the hammer shown in the mockup!
Have you considered any particular treatment for the left side of the stock at the lock area? Perhaps an engraved dummy lockplate or a serpentine or some sort of filigree? Most of the originals I've seen have looked downright plain in this area, and even lots of the better-quality rifles (both old and newly-made) seem to me like the makers formed this area as some sort of an afterthought.
Regards, Joe