I agree with Rick's comments. How much or how little a modification makes to the value of a Sako depends on who is buying it and for what purpose. Just as no two buyers usually agree exactly on what the price of any one original rifle should be, no two buyers agree exactly on how a modification (replaced pad, removed sight, replaced sling swivels, drilled receiver) impacts a rifle's value. Like the attractiveness of the wood, it's an "eye of the beholder" thing which varies with the beholder. There is no "right" or "wrong", merely that some buyers perception of value may vary up or down from the median more than others. That's part of what makes collecting Sakos (or any other collectible) an interesting art rather than an exact science.