I have both above references, but not handy at the moment . From recollection, the Pre '64 Model 70 Featherweight was introduced in the 1952-53 period as the hollow bolt handle era was morphing in for the entire Model 70 line. That would be somewhere in the 200,000 to 300,000 serial range. Sorry at the moment I can't be more specific, but likely someone along with the Roger Rule book under their pillow, or to recite by verse! Also the notation, your rifle should be in 308 Winchester if in that early Featherweight 'solid bolt handle' era and original.
To my mind, all other things being equal, such an early 'FW' rifle slightly more desirable than the later editions. To me the only downside of the Featherweight is the lower 'survival-pristine' incidence of the alloy bottom metal; quite subject to scratching & general finish wear.
Good luck and...
My take
