Thanks VanMan, you hit most of the high points.
Just for clarity, all Grand Power pistols are shipped with two mags from the factory. I'm hearing that some of the remaining stock from the old distributor may be shy a mag. My assumption is the second mag was used to fill requests for spares. All I can say is I hope your purchase price reflected the missing mag.
Baring misadventure, there are tons of spare mags coming with the order shortly.
As for modifying Grand Power slides for Production Optics, I have some comments.
1) I can't make any promises about the guns functioning with the added weight of the mount and scope. I like the idea, but you are your own guinea pigs my friends.

2) If you are planning on milling the slide, you may want to look at the Dynamic or X-Trim models as they don't have the firing pin safety to get in the way.
3) If your slide cuts need to get down into the firing pin channel behind where the firing pin spring sits, It may be wise to look at the X-Cal firing pin as it's flatter to accommodate the elevation screw.
I don't check in to CGN often, so PM's hear are often a waste. I won't violate board rules but if you check out the factory or the Grand Power Canada website, my contact information is available.