Vintage Ink Bottles Set of 2

I have had these for years, They are heavy glass, clear. bottom edges are pebbled for non slip I think. I was told they are for ink. they are pushed in on one side and bowed out on the opposite side, with 2 stright sides. very interesting. half holds the ink and half at bottom are hollow. please see pictures. nice old pair with markings on the bottom. covers are metal. markings: 106 mil at top of bottom at bottom sides 6 one side and A at other side. there is a small square in the center but I can't make out the letter. looks like the Hershey glass. ?