73 and 74 are the same fenders and deck 74 only lock assy is different.
72 fender will work but has different wheel arch, not to mention one year only and much harder to find. 71 is same dimensions as 72, but marker is different and much higher demand.
AMD does NOT make a patch. Goodmark/Sherman makes a lower half quarter patch. The lines are good but it is thinner metal.
Tabco is supposed to be the bomb on the quarter patch for these cars, but I haven't personally seen one.
Buckets from any 70-77 B body will work but there are subtle technical differences.
A body buckets from 70-76 will also work.
Tracks from all above will also work but there are a couple different heights.
I'm 6'3, so I like the lowest ones possible, which IIRC are the 71-74 B tracks.
I have a suspicion that 71-74 bench tracks might work, seeing as how the bucket tracks-
A: are interchangeable left to right, and B: have no lock and release cable for the inboard track, like earlier years. When I get a chance I'll verify.