Yup, you are right for both : Seam on the wrong side, and already discussed a lot
When I did A3 download mode, I choosed to put things like this to be able to recognize repro boxes more easily (once again thanks to all ebay repro sellers...).
A lot of time passed by, and I never saw a repro box exactly the same as an original one (even though some people claimed to have found the perfect printer)
So I already decided to revert seam side.
Then, the only question is when I'll have the time to do it ?
I hope by the end of this year