> How do you know that your boardset was a "matching" pair in the first place? If there > are no serial numbers there's no way for you to tell?
They are "matching" if "Street Fighter II - The World Warrior" uses the 89626A-4 board. Of course I don't mean that the A board and B board have to be from the same shipping. That's impossible anyway since the B board that I want to use for playing is one that I already own, not the one that comes with the A board. (Because my B board has a very specific revision of "Street Fighter II".)
Let's compare it like this: I don't care that the "Tetris" cartridge that I'm playing is not the one that came shipped with this specific Game Boy. But I insist on playing "Tetris" on the original classic Game Boy, not on the Game Boy Pocket, even though they are technically interchangable.