+1 for @Hammy -- Bought a genuine Neo Geo MV-IC Memory Card/Headphone adapter with the original cables. It was heavy and ended up costing him a lot more to ship than the price we agreed on. He met me halfway with the extra shipping which is a stand up thing to do.
Finally tested it this weekend and it works perfectly and is in better condition than he described. Dusted it off, and it's like new.
One of the nice guys who always has great warez at good prices, keep an eye out on his sales and Multiz A+++++++