Hello litig8tr,
No, the correct magazine would have been the magazine originally issued with the pistol. This could have been an aluminum bottom numbered to pistol or black plastic. The only thing that makes it a so called "Black Widow" is the grips and of course we know there are a lot of American made "Black Widow Lugers". The reason people like to add the black plastic magazines to the pistol is to try and make it look like it has original magazines that don't have numbers. Hope this helps.