With this being the 2nd Eduard P-39 I have built, I can say it again... this is a beautiful kit. The only fit issues I had with this build were self inflicted. The resin pit needs a bit work getting into the fuselage, and this was complicated a little more since I was adding the engine as well. The only way to get the fuselage together was to give it a little twist and gluing small sections of the seam at a time, letting that cure, and moving down the line. This created problems at the wing roots and the canopy.
The wing roots had wedge shaped gaps, wide in front on one side and wide at the back on the other. The bottom wing was glued in place first as straight as possible and each upper wing root sanded to mate with the fuselage. The lower wingtip on side was about 1/16" long as a result and was trimmed and shaped. The canopy looked like it was going to be a real chore to fit. It was off all the way around. By what turn out to be luck, i chose to work on the windscreen at the front first. For whatever reason, correcting that made the whole thing fit on all side. After that the build was pretty much straight forward without any problems being encountered.