Nic-a-date is ferric chloride, the same chemical used to etch the copper patterns in electronic circuit boards. It etches away the copper and leaves the nickel. Yes it damages the coin, that's why people use it only on dateless nickels because you can't hurt them much more anyway, but I do know of someone who found a 1914-D nickel this way.
I thought I would try different lighting or some type or black light to check would be a safer way to check.
There will be other "Findings" in your collecting efforts, so label a can or box " Findings of Days past" and write a novel and become famous... Jim
Good P1 candidate. You need to take the photos before you put them in a flip. You will get much clearer photos. I wouldn't touch the coin with vinegar or nick a date.
Your nickel is not in very good condition, it doesn't make sense to send that nickel in to be graded. No date, poor condition, no grade, equals a body bag. Your choice, if you like it hang onto it, if not spend it. Better luck next time!
Given its condition I’d have fun with it. I found two 1918/8 over 7’s playing with nicadate and although it was possible to determine the variety wo/it there was a strong market.