Vintage Grateful Dead PIN Reckoning Rick Griffin Album Art Metal Enamel 1980s

This is a pretty rare pin from the early 1980s. The back does not have any marks of identification. 

First photo is taken with phone under brighter lighting. The rest of the pictures were taken with a digital camera. 

Pre-owned and used condition. From the early 1980s. There is a lot of visible wear. See photos for assessment. The back snaps on the post but has some quirks.. Sometimes it fits loose or goes on wonky.