PLEASE HELP -- Slingshot help needed

[Newbie Collection Agency]

I bought a new pair of Slingshots graphite irons from a supposedly reputable seller (older model, not OSS). They all look fine, except that one of the irons has a different head -- rather than having the Nike Swoosh on the back of the head, it says "SLINGSHOT" in some kind of stylized font.

Obviously there is a problem that one of the irons has a totally different head than the rest -- all the rest have the Nike Swoosh on the back. But I've never even seen a Slingshot iron that says SLINGSHOT on the back of the head. So my question is this: (a) is this odd iron that says SLINGSHOT a legitimate Nike iron but from a different year Slingshot model, or (b) is this a total knockoff, and Nike never even made a Slingshot that says SLINGSHOT on the back of the head.

Any help would be very much appreciated. I want to contact the seller ASAP and want to know what I'm dealing with. They are all wrapped well and look new (in plastic, and the head wrapped a 2nd time in plastic), but of course this is a mix and match set at least for this one iron. Thanks very much.

[iacas]

Call Nike. Companies like that take the counterfeit business VERY seriously.