Interarms/Mauser magazine ID

I recently purchased a 6" Interarms/Mauser Parabellum. The magazine that was included with the pistol did not have any Mauser markings on the spine like others I have seen, but the seller said it was the original magazine. Is there any way to tell if it is genuine Mauser or not? The base is black plastic with concentric rings in the dished out areas of the base. The follower looks to be chrome or nickel plated steel. Please let me know. Thanks.