Hello! I guess you are concerned about white marks on his bottom and top shell. It doesn't look like shell rot or fungus to me. More like chipped off keratine layer. Photos of the top are a bit blurry.
Are this white spots are "fluffy", is there any fluid from under the scutes?
Shell fungus and rot are very rare among tortoises (with the except of humid loving species like redfoots).
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