Metal Slug 3 AES

Doesnt seem so - only the US sticker.

bought this one from a reputable seller back in 2010 on this board so I never doubted it.

maybe HeavyMNachineGuns theory is right - I will try to visit a friend of mine who has checked all his games for their chips - so I will take all my high-value games to him and get assurance once and for all..

All US versions of MS3 I encountered have the dark grey boards (mine too). Anyone has a picturewith the grey/green combination? Maybe you are mixing it up with MSX, since this has the grey/green boards.

Well, it's entirely possible SNK had stock left over from the Slug 3 1st print to cover the NeoStore USA version. You need not worry about authenticity though, the dark grey PROG board is a good sign.

It's just over on MVS, it's generally accepted that Slug 3s with green PROG boards are part of the 2nd, post-SNK corp print run. The same should be true of AES with its 2nd print run. The NeoStore USA version was released after SNK Corp's closure, thus why it should have a green PROG board, but I guess that's not the case.