Welcome to the Forum. You have a nice 2nd Model there, but the walnut stocks are not original. You will find pictures of original stocks posted here and they all had the large gold medallions in the top of the stocks. These come up for sale and you can search ebay and Gunbroker for a set N frame grips. With the crown over 30, I think that indicates Canadian issue. Is there a "C" stamped anywhere? Is the 455 barrel stamping unchanged?

Check out this thread and you can find more information about 455s.

Long barrel 1914 S&W .455 revolver