Welcome to the Forum. Great rifle but I am not as versed as others here with identifying these types of rifles. That said it is very helpful for us to be able to see more of the rifle to get a sense for the architecture of the piece. Having a photo that shows the full view of the rifle from 6" forward of the lock of the rifle to the full butt stock as well as the opposite side of the rifle showing the side plate, cheek section and butt plate. A full length shot of both sides is also helpful. The clues revealed by the details can help. The area some times can be determined by these nuances and narrow down where to look for the C S ? signature. Late percussion guns can be difficult to sort out due to the use of readily available hardware for the gunsmiths of the late 1800's. Thank you for sharing pictures of your rifle. Having more photos will help. I look forward to seeing them.