Complex sentence: Some Appalachian men were able to make their own hunting rifles and musical instruments, as well--today both of these crafts remain highly developed in Appalachia, while they became industrialized elsewhere in the country.
Split into simpler sentences: Some Appalachian men were able to make their own hunting rifles and musical instruments, as well. Today both of these crafts remain highly developed in Appalachia, while they became industrialized elsewhere in the country.