Thorleif是索瑪方塊的骨灰級玩家，他創建的網站Thorleif's SOMA page運行多年，是索瑪方塊玩家的福音和聚集地。
This is a really nice figure that you have made - And a pretty presentation on your webpage.
I checked the database, and have to tell you that Mr. Courtney Mc.Farren described the same here.
On the page "SOMA Figures CS1 Spirals" the figure 019 in the figure.
However Courtney never informed the solution.
So I have added your solution to the description text, near the bottom of this page.
Thank you for sending your figure