In the past I asked for help with a smoke-coloured version of this pattern, but the thread got a bit distracted so perhaps this time....
Here is a gateau plate with side-plates in amber.
http://glassgallery.yobunny.org.uk/displayimage.php?pos=-6528It's really a beautiful use of the technique but I'm not sure what the technique is!
My guess would be that the plates were pressed in a flat mould including the impressed design which was then 'satined' by hand?!
From the surrounding design I'm thinking of German and Czech factories as prime candidates?!