Glad it helped, Belaar! I'm always excited to see people using Sketchup for 3D printing.
Good thinking about using Curviloft to fix the tiny bit
I'm also familiar with printing from Shapeways, and the only thing I would suggest is to add a small radius to the top and bottom edges so the final model isn't sharp. It might be easier to do that before bending.
I made a couple comments in the attached model about the smoothing and making the model ready to send to Shapeways.
Finnished ring.skp