Cello Violin Viola Made In Czechoslovakia Enamel Pin

Hello. I got these from an estate sale. What I know about them is that it seems to be enamel. It measures approximately 1 1/2" in length. It is stamped "Made In Czechoslovakia." The detail is wonderful. If you look closely you will see actual wire strings. It is not stamped silver and I don't believe is. It has a c hook on the back. I can't seem to find out anything on these. Was curious as to how old they may be. If it is a c-hook does that make it around 1900? I have maybe 20 of these in 5 different colors. Again the detail is great. Any info would be appreciated.