legit cia? well, this is nothing specific to that.
"can i restore a save to an eshop game?" "can i restore a save to a game card?" - yes.
it depends what format the save you have is though.
if you backup the save using the save plugin, you can restore it fine. the format is the same as made by sdf, it is decrypted.
- you don't expect this question to be asked for every individual game do you?