I think that once in each game you may be able to find a red or blue kin in the same general area. For instance I know there is a red kin by the wheelbarrow in Melari's Mines and I dig for it. I think perhaps the red kins especially are preset once per file. The green ones are so plentiful they turn up in the sam spot often during a file.
I know the big 50 Rupees are a one time per file only deal. I m currently doing an offline file of the chests, every chest in the game. And may I say, there's a lot of chests in this game. I'm just getting to Wind Palace.
But you could keep track of the kins to note where they turn up in a dig then test the spot again maybe ater the next dungeon. Good luck! --- Zelda Game Boys Hangman 13 - http://bit.ly/n4bzUn - This game is for fun, not thinking. See you there!