Spectacular work! What kind of tang sight do you have in mind?
I'm a big believer in tang sights, especially from Montana Vintage arms.
https://montanavintagearms.com/sights/
I've used most of those and especially like the #131 on a lever rifle.
This works well also, but is not as repeatable as the verniers.
Patterned after the original. Two sizes of eye discs included.
montanavintagearms.com
Picking the right sight can let you use your barrel sights as well as tang for different ranges and situations.
Is that a thumb lever on the hammer spur? Those are usually reserved for use with a scope. Will it be removed?
Looks like you will ready for the coming hunting season.