position of dash defroster vents

Also look for part numbers. If it ends in an odd number it goes on the driver's side of the car.
Looks like it slants toward the firewall in your pic, I checked which on fits that configuration and the part number ends in 7 (odd) and that confirms it.

The repop vents require slight enlargement of the mounting holes. No big deal but would have been better to have done it before paint.
It's true that I can fix it, what bugs the sh*t out of me is that I would have to. The fact that somebody couldn't take the time to test fit a prototype before popping out hundreds of them really grinds at me. I finally rooted around in my boxes of stuff until I found a nice set of originals.