Coca-cola 30yr. service Tie Clip

This is a Coca-Cola tie clip my Uncle received for 30 yrs. of service, at Coca-Cola in Indianapolis, in the mid 70's, early 80's. There are three small diamonds next to the coke bottle. On the back it is marked 1-20-12K GF. I believe it is gold filled. I have no idea the size or quality of the diamonds.
Any information on the value of the clip or if it's collectible to others?
Thanks, in advance;
Lumpy