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.