cocktail glasses like at barrelhouse flat
They are Libbey 7oz Embassy Footed Rocks glasses, part #3747. There is also a 5.5oz version, part #3746, possibly preferable for home use. They should be available in cases of 24 from any restaurant supply store that carries glassware, as Libbey is one of a few standard brands of restaurant glass. Krasny & Co., on Clybourn north of Diversey, will sell them by the dozen if you are willing to pay a case-breaking fee. I'm not aware of any retailers that sell them by the individual piece or set of six.