This is Simplicity 3737 (now out of print), view B. You’re looking at the bottom tier of the inside layer – which itself is two layers of dress net/crinoline, edged with satin bias tape.
I still have to make the outer layer, and attach it all to the yoke.
So far I’ve been working on this for three days, and the biggest difficulty I’m having is the amount of space it takes up!
I’m perilously close to losing my temper with this, so I think its time to pack it away and work on something else for a while.