[Zack The Ripper]

Just to clarify, true green Elcan sleeves aren't OD, they are CAG (Canadian Average Green) which is slightly lighter than OD. Yes I nitpick, sue me. :-P

You're best off searching for a used real steel one as the replica dimensions are generally not quite to spec with the RS C79s. Nothing better than the real thing if you're building a true AS replica. They are not a controlled item, if that were true then many-a-folk would have been nailed for owning them by now. Just be careful where you decide to pick them up from, not for legal purposes, but simply because you may get charged a ridiculous price for a repro piece. If Viperfish is selling some sleeves and stating them to be the real thing then personally I would trust it; haven't heard or seen anything negative about him. This said, the real sleeves likely won't fit on any replicas.