Replica can mean a newly manufactured firearm of a design that an orginal would be a Curio and Relic.
Example: Winchester 1892. Originals will be over 50 years old, so they are C&R rifles. New ones made by Rossi, Puma, etc are NOT C&R eligable. These are "replicas" of original guns. It's the manufacture date of the firearm that qualifies it, not the design.
You might check out cruffler.com for more answers.