Okay 3.0 hours of deriveting, disassembly, fighting a couple rivets that did not want to come out, clean holes, debur as necessary, reprime all parts. 1.5 hours of reassembly, slipping the rear spar attach bars into place with the correct orientation and re riveting everything back to where I was Friday afternoon when this "oops" was discovered. I can only image how disappointed I would be several months down the road when it came time to install the wings and proper edge distance became a real issue.
Now, how did this happen I have asked myself several times over the weekend. As an A&P IA, former Chief Inspector in charge of Quality Control for a large helicopter firm, I felt I was as cautious and careful with details as most, if not more. I remember clecoing the rear spar attach bars in place and one was inverted as the outboard tapers did not match. I flipped one around so they both matched. I looked at it for a couple seconds and thought to myself, "Can it be installed wrong?" This is where complacency and confidence in Van's caught me off guard. There was a note in this section regarding the orientation of the gussets but nothing regarding the spar attach bars. I told myself in a fraction of a second, there were no notes on the orientation. It is either "Murphy Proof" or it doesn't matter.
This morning I looked in the instructions later in the construction manual and found the big bold statement regarding edge distance when locating the rear spar attach bolt. What could be better? A note in the section when riveting the rear spar attach bars and/or on drawing 65, even better would have been one or two holes out of alignment with the rest of the rear spar attach bar to bulkhead to make the orientation "Murphy proof". Lesson learned, Always watch for "Murphy" to sneak into your practices. If not sure ask, reread, double, triple check the drawing. When you ask yourself, "Can it be installed wrong?" Make sure.
Thanks to Paul and Mel for their speedy response and confirmed my gut reaction that now is the time to fix, regardless of how bad we hate to undo something. More than worth the small price of admission to these forums!!