I feel for this wind racing brother. You wait so long with such excitement and then argh! The guys at North will be on this for you I'm sure. Way cool group! With all the standardization now a days, it's critical to have the geometry precise! You can't refine without fine lines... Damn, I should write a song on that one! Good luck to you and get stoked!

The forward tip of the aft box is correctly centered.

What is wrongly placed is the aft part of the box: 308.5mm to the left and 302.5mm to the right (see pics 1 and 2). Had it been correctly centered, it would be 305.5mm to each side

So the offset is about 3mm to what should have been the correct position. It's enought to make so that, at the forward fins station, the trasversal distances from the forward fins to the aft fin extrapolated line differ by 2cm (pic 3). At the nose station, the offset is probably around 10cm.

What is the distance between the front and back fins lengthwise?

Stan

Sorry Stan, I didn't measure it and don't have access to the board anymore (it's in a sealed package waiting to be picked up, to be returned to the importer)

In this pic you might be able to have a rough idea though
(the distance from one front fin to the other is 54cm)

That's nasty , I've heard the rumors now I've see the pics , how could that slip thru QA? Any kites or boards being made in Asia need to be seriously controlled and inspected thru all stages of manufacture.
Think some of these kite companies need a wake up call , this is not good for kite board racing , if production boards need to be used as per the class rules , these guys need to get there act together.

How can you tell without a strait edge?

The line passing through the aft fin box should be equidistal to the front boxes.
At the board I received, such line was 2cm closer to the right-hand box (left, if seen from the bottom) at the front fins station.

Since the forward tip of the aft box is correctly positioned (equidistant from both front fins extrapolated lines), it results that it is the aft tip of the aft box that has been misplaced. I agree with you that, since the edges are not straight at this station (aft part of the aft box), it is impossible to measure the exact offset there. So I estimated it by measuring the distance to the point where the edge transitions to the tail.

I thought that might be how you are measuring. Could be that the tail edge is asymmetric. It would be easy to check if you had a clear t square like the one greenlight surf supply makes.

Yes Glenn, it's very much likely the left and right tail edges are asymmetric.

The aft tail edge, for one, is completely off square (not perpendicular to the long axis of the board), which is evident by just glancing at it.

Anyway, I took those measures just to try to answer to ChristoffM's question.
The main issue in my opinion is the angle the aft box presents in relation to the front boxes, which exists regardless of the edges and is unacceptable to say the least.

Update:

This week I got refunded by the dealer, who also arranged an international freight back to the importer. Thanks Lonasport for your professionalism!

Can't say I'm also happy about North though....Their lack of basic quality control made me lose way too much time this season