@brandutchman & @reilley It appears to be slicer related, I opened the stls in 123d and took down the sizes. When opening in Cura they had lost a number of MM in almost all directions. I think this combined with me changing orientations may have exacerbated the shrinkage. I have since resized and currently reprinting parts 7 & 8 if the alignment and sizing is correct I will be able to do the ear panels and it will be on to bondo and clean up. Future thinking next print Ill open each file and piece together in one large 123d file then copy down all sizes and make sure of them when loaded to the slicer. However before that next print Ill be doing a well run calibration of stepper motors and nozzle output. Ill post pics as it goes, hope you guys progress is going well.