Ok, I'll buy that as my 69 Firebird Conv also has the ones on the left. That doesn't really explain how I ended up with 6 of the other ones on my 67 Camaro.
I seem to recall that when I restored my 69 Firebird 20+ years ago that the screws in the back bottom corners obscured by the seats where different than the others. more like the ones on the right. Of course I replaced all of the screws back then, so no hopes of verifying my memory in that regard.
The picture below indicates the area that I am referring to.
Thanks for your replies to my post.
-Chris