I've provided a way for you to demonstrate that I'm wrong. Simply go into the nearest gun store wearing a mask.
Unfortunately for you, the ways in which I can prove you wrong are not limited to what you "provide". Even "prove you wrong" is more than I need to do; I need merely point out how you have not proven yourself right. I have shown how your cited evidence fails to support your claim, and you have not defended it. You, as the one making the assertive claim, are the one under the burden of proof. So the fact that I'm not going to do what you ask doesn't say what you want to think it does. And you know it.
One of the posters claimed that there were no such laws. I proved otherwise.
You "proved" that your claim is less than 6% true, which you would have known if you had actually read your source. Remember: three states out of fifty (and zero cities, but we'll get to that later), none of whom have been shown by you to be enforcing these laws in the context you claimed or defending them in court. Since your original claim is a blanket statement covering the entire US (assuming that you only meant the US), this isn't even remotely enough to show that your claim should be accepted as generally true everywhere.
Now, if you want to show that those laws are not in effect, do so, and pics or it didn't happen.
Again, burden of proof. You're arguing from ignorance here.
There is on constitutional right to go around wearing a mask
Well, first of all, there doesn't need to be. Ninth Amendment: "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.".
But we need not fall back on the Ninth. Wearing a mask has two primary functions: self-expression and anonymity, both of which are amply protected by the First Amendment.
Therefore, any laws against masks can only pass Constitutional muster if tailored to a very narrow scope. Those of California, DC, and Florida would probably survive since they focus on the use of masks to aid activities that are unlawful anyway.
New York's did survive a challenge, but don't get excited by the headline; read the article and you'll see that the reasoning was tied entirely to safety issues arising from the fact that the plaintiffs were seeking to hold a KKK parade in their hoods, and it was held that the hoods did not convey anything that the robes didn't. Obviously the same could not be said of, say, a protest by Anonymous, and certainly not to someone just walking down the street as in your original statement of "You have a face that's publicly viewable when you go on the street - and you don't have the right to wear a mask to hide it". Note also that the court recognized that "the law could theoretically
be applied in a manner that violates the First Amendment’s protection of expressive conduct,
also referred to as communicative conduct or symbolic speech.". Applied to a case like Anonymous where the mask is essential to the message, or to an individual, the law is far less likely to hold up (it doesn't even apply in the latter case anyway).
And if New York's law has chinks in its armor, then those of North Carolina and the Virginias, with their broad scopes, would get chewed up and spit out like Chiclets. Assuming they even get enforced in the "walking down the street" context of your original claim, that is.
...and various states, as well as municipalities, prohibit it.
Prove it, then, and furthermore prove that said prohibition - and NOT against Klan rallies and the like, but against individuals going about their business (as in, I find myself having to repeat yet again, your original claim)- has been upheld as Constitutional in jurisdictions covering enough of the US to that it can be reasonably said to apply in the US generally. Anything less is not sufficient to support your original claim. Don't like it? Tough; you shouldn't have made such a broad claim when you couldn't support it.
It's not up to me to go through the ordinances of 10,000 cities and towns to see which municipalities also have similar restrictions.
It most certainly is. You made the claim, so you accepted the responsibility to prove that claim to be correct. If you refuse to do so, then your claim is rightfully disregarded. And you have, so it is.