Depends on the years.

It’s actually a Die Crack not a Die Break.
As Bill stated, no added value for a small crack, they are just too common,
especially during the war years when dies were pushed to the limit to preserve steel.

Either a worn die or a worn coin. All the numbers look slightly thicker.

As you say, it is just damage from being “squished”. Hard to say exactly how it happened
unless you were there at the time. Doesn’t really matter though, damage is damage.
Still worth 5 cents though.

Colonial Acres in Kitchener have two for sale on their website, a VF and an EF.

Where about are you in Ontario?

Click on the pencil icon. You should be able to change the heading.

Yes, there is a small Die Crack ( not Die Break) between the tail and rim.

Then you should have put this on with the original post.
This makes no sense and causes confusion with it by itself.

????????

Definitely damage. There is no way that could happen when the coin was struck.
Looks like someone had too much time on their hands and was trying to create something.

Those would be the 1967 Centennial sets. There were many different after market sets produced
to try to entice buyers. Although they would have sold at a premium, plating them has devaluated them.
Right now to a coin collector, they would just be worth the value of the silver in them.

The last Theissen-Crow prefix was EBX so there were many prefixes after AUN.

If you are going to weigh coins, you need a scale accurate to two decimal points.
The fact that your silver coin weighs the same as a copper cent verify that it is just a plated cent.
If the plating was missing, it would show as a weak strike.

Die chips and die cracks are not errors, they are part of the minting process
so they would not be recognized if you sent them in for grading.