They all look like well struck business strikes to me. I don’t see the squared rims I usually associate with proofs. Still pretty especially the 64,
This is what you should see with a proof. I agree that the ones you posted are business strikes. Some of those can be quite prooflike. As a counter-example, this is a business strike that is not too different from the 1890 proof, above. But notice that there is a planchet flaw in the left field, which indicates that the planchet was not polished smooth before striking. The denticles are pretty good, but not as sharp as the two coins above, and the rims lack their sharp and even shape.
Squared rims are associated with proof coins because they are struck with higher pressure, and most times struck more than once, thereby bringing up the higher detail........
I'm not an expert and mostly deal with moderns. I have absolutely no knowledge about more classical coins and what the subtle nuance of 'proof' would imply. But I do think @ldhair might be able to shed a bit of light.
Well, thanks everybody for your for replies, and for the instructive pics @RonSanderson . I thought I may have something with the 1882, and possibly the 1864. The '82 was sold to me as 'ex proof' in the late 80's, so that is a bit of a letdown, actually.
I am not sure if these are the best pictures to help, but I thought I would try to find a year where I had both a circulation strike and a proof. At top is the proof, followed by the business strike. The squared-off rims applies to both the inside edge where the fields of the coin meet the rim, and the outer edge where the rim might be as sharply angled as, say, the edge of a counter-top. The business strike has a light reflection that shows how the fields curve upward into the rim rather than maintaining a total flatness all the way to where the rim rises up. There isn’t a sharp 90 degree angle, as there is in the upper photo. Also note the flatness of the face of the rim, as if you could drive a miniature car all the way around the coin. The outer edge, where you would stand up the coin on edge, shows a similar flatness, although I don’t have a photo of that.
You guys covered it pretty well. I don't have much to add. It's nice when the coin has mirror fields and square rims. Makes it easy to call it a proof but not always. @physics-fan3.14 I'll guess there are some PL coins out there with square rims. The sharpness and detail in the design on the devices is a good sign as well as nice flat tops to the lettering and date. I'm sure that a fresh die with a strong strike could create the same look on an MS coin. Images fool me. You don't always see all the detail that is actually there. To be honest, I reach for a Rick Snow book all the time.
There are several examples of prooflike business strikes using proof dies. However, it is the squareness or roundness of the rims that is often used to determine whether it is a true proof or not! So, a business strike PL will have rounded rims. Here's an excellent example of that: we know this is a proof die because of the eagle type, but if you look at the outside rim it is rounded.