The cart is completly original... here are those pictures for everyone to see:
The wavy lines you are speaking about, are they all over the screen EXCEPT at the Neo-Geo logo? I had this problem with SS4 and a few other games, it turned out to be my 4 slot that was going bad... The 4 slot eventually died on me, power surged. I would take a look at the power levels on the harness with a multimeter. Make sure that +5 and +12 are right... the +5 is give or take, some people like it closer to +5.25, I get more problems there though,
-Nick