Craig, The two small holes just forward of the bolt handle are for mounting a Lyman #48 receiver sight. The stock has been trimmed or the sight as well. Appears very professionally done. The larger hole at the forward receiver is a gas escape hole, which is part of the design of the rifle. Have never used the S&K mount. It does mount where the Magazine Cut-off is. I hear it is pretty solid. There are some YuouTube.com videos of it being used with the 1903.Worth a look if you are considering it. Good luck.
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