Animal and letter blocks

Not sure if I should call these blocks or plaques as they are probably 2 x 2“ square but only three-quarter inch thick.. i’ve had them for year& or only have nine however, they are a different letter on the front and the back so you can make up quite a few words. The different animal etchings are excellent, and the letters are painted on and slightly etched. I’ve searched quite a bit, but haven’t found a similar design to compare with. Some are in quite good shape, I but others the etching is wearing down, and the painted letters are wearing off. I wouldn’t touch the etching but I was considering touching up the lettering. Is that a no, no?