I'm sorry, I thought you were purposely trying to confuse the guy who asked the question. My bad.
BTW, I do own a Glock 17 Gen 4 and originally purchased it as New York legal 10rd gun about 8 or 9 months ago. I also have 17 round mags for it. The 34 uses the same magazines and frame as the G17. I'm curious to see what the salesperson was trying to show you.
Nope, I definitely don't try to confuse people.
The salesperson showed me a "Glock 17 Adjusted" (as she called it), and the walls of the grip appeared thicker than normal. No way for me to tell, because I didn't have a camera on me to compare to ones at home.
That's good news that the mags will fit!
-John