Slabbing a coin, to many coin folks, means to have the coin professionally evaluated and encapsulated by a coin grading service. What you have is not a slabbed coin. What you have is an IHC in a standard plastic coin holder. This type of holder is available at my local coin shop, so nothing special there. I don't think it is even moisture resistant, but on that I may be wrong.
As as to the blue sticker, it is a blue dot sticker. That is all it is. One can find similar stickers at just about any office supply store.
As to potential errors, there is too much wear on the coin for most errors to be evident.
Time for coffee.
Edit: Just noticed you double posted your question, including pics. All this accomplishes is confusion due to answers being spread through multiple threads. If your original post is not in the appropriate section, the moderators or the administrators are able to move it to the appropriate section.
Need more coffee. And probably something to go with it.
