Wii savegames are in /private/wii/TITLE/XXXX/data.bin (XXXX is the game's ID). This format is used for real NAND savegames.
Save game manager GX uses a setup similar to emunand, so a savegame would be in /savegames/000100014e415250/
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Now if i understand correctly, you have a MK Wii data.bin savegame that you wanna transfer to the Wii.
To use this you have to put it in /private/wii/TITLE/RMCE/data.bin on a
SD card .
Then go to Wii menu-->settings-->data management-->save data-->Wii-->SD and copy it to your realnand.
Now, once the save is installed on realnand (or even an emunand if you use one) you can extract it with Savegame manager GX and puti it on SD, HDD, wherever you like.