No. A person could purchase shavings or powder at auto supplies stores or hobby shops or hardware stores. The shading was the typical #2 pencils at the time. I guess graphite is still easily purchased. After all, it is used as a sort of lubricant. I am sure there are many places that sell it.
White vinegar will just smooth the surface, some. It won't hurt the coin, the coin already won't trade. You soak it for as long as it takes to make out the date and, where applicable, mint mark.
Eddie makes a good point. If you’re not to worried about final appearances, the 50/50 mix works in minutes. As the solution ages with use, the effects of the peroxide are reduced and the finish smoother. Straight vinegar offers the smoothest finish but it will take much longer to reveal a date/mm. So, keep that in mind.
A word of caution about using vinegar. Some of you folks probably know this but I learned the hard way to not soak items overnight in vinegar in an aluminum tray. I was cleaning up some rusted tools and left them overnight in vinegar, the next morning there was a huge mess the floor of the workshop as the vinegar had eroded pinholes in the aluminum trays and all the vinegar leaked out. Now I use a Pyrex dish for soaking.
Guess I could pretend like it is a rare date and worth hundreds, think about how rich i could become (all fantasy)....
Have you posted this cent in the errors section? I am not an error guy but find it odd that the reverse is crisp while the obverse looks like mud.
Looks like a mixtures of acids used on the nickel to try and see the date or the mint mark. The acid is dangerous. I did experiment with such in college lab on my breaks many years ago. It works, but is quite ugly as it affects a large area of the coin. But it is still worth 5 cents