Do you want a safe queen or will you use the M70 in bad weather and lessen the value over time?
I don't think that hunting with a classic automatically decreases its value.
When I was 18 years old, I purchased a Griffin and Howe built on a 1903 Springfield action from the widow of my pediatric dentist. She thought about just giving it to me, but figured if I paid her a little something for it, I'd be inclined to treat it as Doc did. "A little something" turned out to be $250.00 1983 dollars. That figure was arrived at by her asking me what new rifle I would buy and what it would cost.
Doc had that rifle made as a graduation present to himself upon matriculating from dental school. That was in 1927. He hunted with it for the next 56 years on five continents, but it wasn't some beat up old piece of junk when I got it. It had some bluing wear on the muzzle from being shot, and a little on the edges of the Lyman 48 aperture sight it was fitted with, but aside from those minor flaws, it was in fabulous condition. I used it as my main big game rifle until 1994. During that 11 years, I used it in five western states, a couple of Canadian provinces, and took plains game with it on two seperate trips to Botswana. I used it in searing heat, torrential rain, and freezing snow. It looked just as good at the end of my use of it as it did when I got it, and it was worth a darn sight more than I or even Doc originally paid for it. It was what it was -a used, but not abused and very immaculately and lovingly maintained rifle. I don't think the Doc or I put a serious dent in that rifle's value through our use of it.
My first rifle was a Marlin 336 that my dad bought second hand in 1976. I still have it. I have used it extensively for 37 years. It is not some beat up looking POS in spite of riding in saddle scabbards, getting rained and snowed on, and so on. The bluing is still in good shape, as it the wood. I suspect I could sell it today for at twice what my dad paid for it if I were so inclined. It was used, but not abused.
A little over a year ago, I paid $425.00 for an N.I.B. condition Remington M-721 in .270. I suspect that when I am done with it some 40 years down the road or more, it likely won't be worth any less, assuming the Government still allows transactions in firearms to occur then. And I plan on using it until that time.
I have recently acquired some rifles that I bought for my dad over the years. One of these is a Ruger M-77 Ultralight in .250 Savage. My dad used it for 10 seasons. Aside from the bluing being blasted off the muzzle crown from firing, this rifle still presents in as-new condition and my dad shot about 1,500 rounds through it. The wood doesn't have a ding or scratch in it. It got rained on by the same rain my Springfield got exposed to. It got snowed on by the same snow. It got seared by the same heat. It rode in a saddle scabbard when my .30-30 did likewise. It was used, but not abused, and was lovingly and carefully maintained.
I paid $250.00 for it in 1985 or so. I paid another $135.00 for a Leupold VX IIc 2 X 7 compact scope. I suspect that if I were to sell it, it would fetch a darn sight more than the $380.00 I was in to it for when I bought it. I don't have to wonder about that, actually, becuase I bought myself a similar setup at the same time and sold it in 1995 for more than I was into it for.
A few years after I bought my dad the M-77, I bought him a Ruger No. 1-B in .30-'06. This was his "holy grail" rifle, but one he felt he could never justify spending the money on. I paid $275.00 for it in 1989. I bought a Redfield Tracker 3 x 9 scope for it at around the same time, which was about $100.00, if I recall correctly. My dad never hunted with it (he said he wouldn't if he ever got one because it was "too pretty to use") but it was a cherished "range toy" and he shot it every once in a while over a span of 20 years. He must not have shot it much, because there isn't any noticible blueing wear at the muzzle like there is with the M-77. I'll never find out for sure, because I'll never sell it, but I bet I'd get more for it than the $375.00 I paid for the package when I bought it, even though it has been shot.
My dad also "re-gifted" me with an M-48 Mauser that I bought from Federal Ordinance in So. El Monte, CA in 1992. This was refinished to like new condition and fitted with a new 7.62 Nato barrel in Israel in the mid 1950's, then relegated to storage until Fed Ord imported it. I bought two of them for $100.00 total. This rifle has been rained on and snowed on, but aside from some bluing wear at the muzzle from being shot, it is in the same "arsenal re-finished as new" condition it was in when I bought it. I suspect, if I were so inclined, that this would also fetch more than the $50.00 I paid for it. My dad liked this Milsurp more than I ever thought he would -firing upwards of 3,000 rounds through it over a period of about ten years. I don't think that diminsihed its value much. Considering what I paid for it, it had nowhere to go, value-wise, but up.
Another example from my own gun oollection is the 20 gauge Ugartechea double that was the first shotgun I bought with my own money. I hunted with it extensively for 26 seasons, sometimes in rain, sleet, snow... I paid $425 for it in 1983. After a quarter century of hard use, I sold it for $1,200.00. I used it frequently and often in all kinds of weather but I wasn't careless with it and didn't abuse it.
I'm reasonably certain that if I were to buy a pre-'64 Winchester, and if I were to use it as my main rifle for a period of years, I'd be able to use it without abusing it and without diminishing its value much. In my experience, old school blued steel and walnut can take more exposure to elements than people nowadays seem to think that these materials can. Much depends on how they are cared for and how much care is excercised in their use.
JP