I can't speak to the AE/AW skins, but the AT AICS skins are not compatible; specifically, around the notch for the bolt handle (the notch on the AT rifle is noticeably smaller than the notch in the AT AICS skins).
After having ordered some replacement skins for my AT and waiting (and waiting, and waiting, and...), it became clear to me that the quicker route to go would be to just get my current skins Cerakoted. The wait for skins was in no way the fault of the vendor through which I placed the order... it just seems (at least at that time) that AI uses every set of AT skins on a rifle, rather than providing spares.