TCL

Hello all, First time post. Well I am a Numismatist or coin collector/dealer. The problem: Buffalo Nickels. The date on the coin was one of the highest points on the coin, often resulting in the date to be worn off. If I understand the whole minting process correctly, the area around the date is softer, since when the coin was struck, the metal from the "field" gets pushed up in to the design/date. There is an acid that is sold, that when you put one drop on, it draws the date out. The problem is you will go through 100 coins before finding a good one. Well is there any machine out there that will allow you to see the different densities in detail, to see what the date is? Any sort of imaging device? Density scanner? I really don't know what is out there, or if it would even work on metal. Any help or suggestions would be great! Thank you!