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As oldflatfoot said, collectors term this model as a .38 Military & Police Model of 1905 3rd change. About 94,800 were produced during the 1909 - 1915 time period. Yours looks to be a pretty nice example. As for the pearl grips. Typically, by this time, all factory pearl grips had the S&W monogram inserts. I say typically because I've learned that nothing is absolute with S&W. Hard to tell from the pics how well the grips are fit. In certain angles, they look to fit well enough to be factory. Other angles they look to be not flush the frame.

Very nice heirloom. If it were mine, I would surely request a historical letter. The letter will tell you when and where it shipped and its configuration when it left the factory. (if the information is available in the records) Even if it doesn't confirm the pearls ( which it more than likely will not) it is a family heirloom well worth the endeavor.

Very nice revolver. Thanks for showing it to us.

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