Yes, you are correct it is a second model variation. I refer to these as 1914 early production. It is believed these were made in 1913. These followed the Humpback variation which were preproduction or prototypes. Approximately 10,000 of this second model variation were made. I have yet to see one that was factory nickel plated. There are examples of the Sidelatch .25 caliber model that were factory nickel plated and were produced before or around the same time as yours. These second model variations are pre WWI produced thus made for commercial consumption. Because of these 2 facts, a factory nickel finish cannot be ruled out. To verify it being an actual factory original finish would require an in hand inspection by someone with knowledge of period nickel finishes. It would be very exciting to have it verified as factory original. If it is you are to be congratulations on acquiring a rare example.
Regards,