Vintage Crystal Whiskey Tumblers outlet Old Fashioned Rocks Low-ball Glass

Crystal Whiskey Tumblers Old Fashioned Rocks Low-ball Glass.
No chips or cracks
Set of (6).

I believe they are Czech Bohemian but do NOT know the company. They do have an etch or acid mark but it's not helping me to Identify them.
In the photos I have drawn a representation of the manufacturers identity.

They are really nice with an unusual knotched base and they also are fluted.
They might have minor scratches or flaws. Some show some bottom wear. outlet