Yeah,73 will have a push button (looks like a little golf tee) on the top of the doorframe by your elbow like a 68 only...69 -73 has the unlocking mechanism as part of the interior door handle (not door pull) also *I think* the interior door handle is in a slightly different place so you'd need the matching rods to the door you'll be fitting or drill some new holes and use nuts and bolts instead of the factory captive nuts.
So in a nut shell , yeah it will fit, but you need to change a few things and (if you're bothered) it won't be 'right' for the year.
Hth
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