The back of my AT101W (which I did a switch swap with a worn out AT102W) says DP/N 0227KN. Also, all the quietkeys said "Quiet Key" on the front, and were smaller than the ATs. You could always ask the seller to check if it is says AT101W on the back, but I'd be 99% sure that that is the real deal.
There's always the possibility that it could be a rubber dome AT, I think they were called the AT101R or something like that.