Does the right to keep and bear arms protect the right to keep and bear armor?

No, there is no "right to own your own armor". That being said, if you can afford it then I suppose you should be able to own it. I do think there should be penalties against felons owning, possessing or purchasing such armor just the same as they cannot with firearms, especially in the commission of a crime.

I recently stubbled upon an article about silences that contains some interesting verbiage that may have some bearing on the subject of second amendment and body armor: https://www.omahaoutdoors.com/blog/tenth-circuit-cans-unregistered-silencer-sales-suppresses-state-law/
Contained within the article are quotes from the tenth circuit that may actually change the interpretation: “Even if silencers are commonly used by law-abiding citizens for lawful purposes, are they a type of instrument protected by the Second Amendment? According to Heller, “the Second Amendment extends, prima facie, to all instruments that constitute bearable arms.” 554 U.S. at 582 (emphasis added). An instrument need not have existed at the time of the founding to fall within the amendment’s ambit, but it must fit the founding-era definition of an “Arm[].” Id. at 581 (citing two dictionaries from the eighteenth, and one from the nineteenth, century). Then and now, that means, the Second Amendment covers “[w]eapons of offence, or armour of defence,” or “any thing that a man wears for his defence, or takes into his hands, or useth in wrath to cast at or strike another.” Id. at 581 (alteration in original) (citations omitted). A silencer is a firearm [*30] accessory; it’s not a weapon in itself (nor is it “armour of defence”). Accordingly, it can’t be a “bearable arm” protected by the Second Amendment.
Thus, because silencers are not “bearable arms,” they fall outside the Second Amendment’s guarantee.”
Please pay special attention to the portion above “any thing that a man wears for his defence.,
I don't know what this ruling will change in the minds of lawyers and judges.

If we trace the use of the word Arms back several hundred years you will find it to mean "your kit". What you wore/used for defense, plus what you carried/wielded for defense and offense. A Knight's kit was comprised of armor, shield, sword, etc. In today's world, body armor makes sense. What does not make sense is wearing it everywhere.

The militia duty I have would mean I am equipped with what I need to defend myself and friends on a battlefield. Fine. I should have a (small) vault where my military kit is stored. For my everyday I would (conceal) carry a pistol of some sort.

Don't think so. Guessing their rationale is that armor is an enabler for bad actors. Not everyone that wears it intends ill will. Pawn shop owners, liquor store employees, armored car guards, merchants in high crime areas etc.

They're offering reinforced backpacks in the wake of Parkside shootings. So would it extend to That?

Wearing body armor is no different than wearing a heavy coat in the winter. Body armor is 100% passive. It offers no threat to anyone. Armored vehicles are acceptable. "Bullet proof" glass is acceptable. Run flat tires are acceptable. Kevlar helmets are acceptable. Many forms of protective devices and clothing are acceptable.

The right to body armor may or may not be included in the right to keep an bear arms. But whether or not one considers it to be included in that right, one has a right to self-defense, and since body armor is *only* defensive in nature, I consider it a profound violation of an individual's right to self-defense to prohibit body armor.

you forget the 2-3 clowns that robbed a bank several years ago in body armor? Cops with pistols, kept them pinned down but couldn't take them out till SWAT showed up, and then it took awhile.

It only mentions arms, any mention of armor and now its interpretation. We cant interpret our right to body armor and expect others not to interpret what things like "well regulated" and "militia" mean.

Of course it does but that does not mean that government will not infringe on the right as they do the second amendment. Remember that the Constitution does not and never did grant any rights, none, zero. The Bill of Rights does not grant any rights, none, zero. Rights are God given and everyone has the same rights world wide. Our rights are just infringed upon at different extremes depending on the government you live with.

What the Constitution does is enumerate or affirm certain rights Citizens already have separate and apart from government as a means of saying "Hey stupid government, I shouldn't have to tell you but this a right you idiot!". The Declaration of Independence explains it well.

"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.--That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed,"