I see you managed to save a few things (such as the Buster Sword giving +7 to the Luck stat), but the model IDs are unaltered. Try this : go into your weapons tab, change Cloud's weapons' model ID to 00 in the top-right corner, then select File -> Create Kernel.bin. Then close Wall Market, and open it again. If you see your changes, then it's good and all of Cloud's weapons should look like the Buster Sword.
If not, well... ...it's weird. I tried it, and Wall Market sure saves the changes to Model IDs for me. And since you managed to save other things, I can't see how it wouldn't work. Better call Sculler and Muldy.
That's odd... I definitely didn't edit the Buster Sword giving +7 to the luck stat... all I did was change the model ID's to 00...
Also, I created Kernal.bin like you said, closed wall market, and opened it to see if my changes were there, and they were.
I went into the game, and nothing was different, which was exactly my problem before... :/