Hi Tee Bee, I'm slower than you are in this project! I'll finish up a 3D Primo first before progressing on the Corkscrew so it will be a couple of months.
I do have the wing basically framed except for the center sheeting. Like you I am sheeting more of the center in order to set up a bolt on modification. My wing is also modified to have a trailing edge taper like an Edge 540 with less dihedral. I thought about a radical redesign, but that is not what the Corkscrew is all about........it's about simplicity turned into a fun flying model. I wish we could correspond with the designer, Stu Richmond, but I don't think he travels the internet. His input would be valuable, etc.
My aileron servo on the latest version was also upright with a little housing protruding out the wing's bottom. I think it was a "male" corkscrew