I'm looking along the length of the body where the two halves meet up and noticed that they didn't match. Somewhere along the way the right half got bumped up by .01mm. The cockpit lid also got bumped both forward and to the side. Since all the parts go together with screws and all the holes must line up this could have been a total disaster. I had to backtrack through 6 different versions of the project to find where the problem started so I could assess what I had to fix. It sidetracked me for a few hours but I did get it fixed.
Remember to save often and of equal importance is to document what you have done to each file and how they differ. I have a simple text document in the project directory for this purpose.