I have never seen a Model 10, except possibly the heavy-barrel guns, that DID have a pinned front sight. The vast majority of all fixed sight S&W revolvers of all models and calibers have front sights forged integral with the barrel.
The non-pinned sights started in 1899 on the M&P series, and even earlier on the .32 HE (1896).
Did you possibly mean pinned BARREL??