Glad you found your way to the IGKT forum! Lots of people I send there never show up.
Why am I not surprised that you received several quality answers?... The depth of knowledge here is astounding.
Glad to be learning about these cork knots too. And to be discovering the pharmacy book from which SS369 extracted that Champagne knot.
To add a bit of reference info to the thread, here are the two solutions Ashley mentions (you know one of them from our prior correspondence). #371 is a piece of fabric on top of the cork, held at the neck by a constrictor (similar to Roo's suggestion, who instead uses the boa, a "double constrictor").
But the one that really gets my attention is #370. You lay one piece of adhesive tape across the top of the cork, so that the ends come down the edges of the bottle's neck. And you loop a second piece of adhesive tape around the neck, so that it holds the first piece of tape in place!!!
How is that for a suggestion by a master knotter...
Highly practical, though.
I haven't read Ashley from cover to cover, so I was surprised to see adhesive tape mentioned there.
Wishing you all a fun weekend.