Unsure how to make surfaces from three open curves to finish my ammonite design

Hi folks,

I’m leveraging a script from another user, and was able to almost finish, but am getting stuck on how to make surfaces from the spiral curve and each of the offset curves that I made. I circled the three components that I’d like to create the surfaces from.
Thanks for any help/links/pointers you’re able to give!!

ShellFractal.gh (21.7 KB)