Exactly. The air vents and rectangle holes for the armrest fasteners dictate 67 model doors.
I haven't been into a 68 door in a very long time so I cant say exactly what the difference is in the brackets. I like the color keyed plastic plug and hidden hardware though. The chrome screw head showing on the 67 door looks out of place to me, just like the one on the right end of the inst' bezel.
Anyway... I learned today that the weatherstrip moved from one glass to the other at some point.
Just like the quarter windows winder handles being in different locations, they were constantly changing stuff.