IMPERIAL GLASS COBALT BLUE TROPHY OPEN SALT/TOOTHPICK HOLDER

Hi Everyone,

Here is my new little mistery... It is a little toothpick holder or open salt.
It measures: 3'' tall, 1.5'' squire on the bottom and 2 3/8'' tiameter at the top.
I am confused with the marking on the bottom. It is marked as Imperial Glass before 1972-74. But also there is 1984 marked.
As my knowladge Imperial did not use this mark after 1972. So what is this? Who made it and when?
I would greatly apreciate every input. Thank you in advance.