(Did some bolt handles really come off???)
Yep, they are soldered on. Sometimes they don't get a good solder and fall off. If you get a sticky case in the chamber and have to use some force to open the bolt the same will happen.
Most pre-64's are over hyped. The true quality 70's were pre WW-2. All of those command a premium and were very well made. After WW-2 the quality started a slow downward trend, although they are still well made guns. By the late 50's and early 60's Winchester found that it was just too expensive to make a controlled round feed rifle (CRF) and be profitable when everyone else was making push feed (PF) rifles and selling them much cheaper.
In 1964 the 70's were totally redesigned and should have been given a different model number. The new guns were PF and a very different design. In 1963 a pre-64 Winchester was nothing special. Starting in 1964 those hunters/shooters who wanted CRF would pay a premium for a pre-64. Not because the rifle was really any better quality, but because they wanted a CRF rifle and buying a used one was the only option. From 1964 -1992 ANY pre-64 sold at a premium because of the CRF feature.
In 1992 Winchester brought back CRF, Ruger introduced a CRF rifle in 1994 and we also now have Kimber making CRF rifles. Today a common 70 made from 1946-1963 "SHOULDN'T" sell for any more than any other 50-70year old rifle. Some people think they are worth a lot, and some pay a premium when they shouldn't. One of those rifles shouldn't bring any more than about 50-60% of what a brand new 70 is selling for. Rare configurations or calibers will bring a premium just as with any other gun.
The PF rifles made made during the 60's and 70's are probably the least desirable. In 1980 Winchester was sold to United States Repeating Arms Co. They continued to use the Winchester name and made PF rifles of very good quality during the 80's and 90's. These are some of the most under rated and under valued 70's. Great guns that can often be found at bargain prices just because they are not CRF.
Winchester brought back CRF in 1992 and called them 70 Classics. The ones made in the 1990's are probably the best of the 70's. Actually better than anything pre-64. At the same time they continued to market a line of budget rifles with the PF action so you'll still see PF rifles made into the 2000's. Modern manufacturing methods made it possible to make CRF rifles at a reasonable cost. I don't know the exact year but Browning bought the Winchester name at some point in the 90's
At some point after 2000 quality again started slipping and production ended in 2006. Most of those are just fine, but the odds of getting a gun with some issues increases the closer you get to a 2006 date of manufacture.
Browning moved production to their FN plant in South Carolina in 2008. Starting sometime in 2014 they starting shipping the parts to Portugal for assembly. I own 3 of the Classics and 1 FN made gun. All are stellar. While I have no personal experience, I've read a lot recently of poor quality again. Hopefully this will be corrected soon.