Don't worry, i'm allowing you to keep Mamoswine. Focus on fixing the issues present in Infernape.
As for Choice Scarf, mentioning it in OO should be fine. It isn't very good in OU since Mamoswine's STABs are easily abused, its somewhat made redundant by Ice Shard and the Pokemon that used to be susceptible to this set (Sub Chomp / Sub Loom) aren't as common as they used to be.
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