Yes, it is marked with the expected Cordite Proofs as per “pre-1904” (or actually the 1896 proof rules), there was not a specific “Nitro Proof” mark until the updated 1904 proof rules. The 70-480 would have been the “tropical” load typical of the early Cordite years.
I have an 1899 vintage W&C Scott 500/450 3-1/4” top lever hammer rifle so marked.
- Mike