Really interesting rifle. Thanks for posting!!

I'm guessing the bolt mod is merely a personal preference by a previous owner. I have flattened several of mine not exactly similarly but possibly for a similar purpose; the gun has scope bases and possibly the owner wanted a bit more hand clearance between the knob and the scope. That is why I did it. I am left-handed and have modified mine to allow easier and more secure grip on the bolt when reaching over the top. This one has a right shoulder cheekpiece, but nevertheless, the previous owner possibly just wanted better purchase of the bolt handle. Particularly when wearing gloves as I frequently do when hunting, it works.