Now that I've got the parts that I need I'm planning to strip the 3x9 Sora equipped Allez completely, send the frame and forks of for repainting and new decals and then rebuilding it as a 2x11 105 set-up.
Some of the parts I have been accumulating are used 50/34 crankset and brifters. New parts will be the front and rear derailleurs, cassette, pre-waxed chain, headset bearings, bottom bracket, wheel axles and bearings and 11-speed freehub. I'll be re-using the Sora brake callipers but having them black anodised rather than painted to give a more durable finish.