Go to mvs-scans to check and compare, or next time, open the cart up and take a picture of the boards if you know the label is fake or can safely pull out the boards without creasing the label.
The boards are likely real unless people started bootlegging Windjammers due to its recent popularity.
The blue case and label are fake. A replacement.
That blue shell looks nice for a replacement case though. Wish NG Dev was using them for their recent re-releases.
Those blue shells are a bit shit (the Windjammers one, not NG Dev's blue shells). They dont fit properly and the screws frequently break off.
The blue ones were designed by Yaton and manufactured in China originally for the Chinese market. Once he started exporting those carts en mass, the blue carts could then be found all over the place. TBH they aren't terrible - the fit is decent enough and they are very similar to the originals. I've seen a number of other black/clear cases on bootlegs with matte finishes that are absolute trash.
I used to have a copy of Razion that came from NG Dev in a blue shell that was very solid. I assumed that this shell was the same, but I'm not surprised to learn that it's cheap Chinese crap. It still begs the question though - why didn't NG Dev keep using their blue shells? I hate the shell on my new Gun Lord reprint.