A Body Seat Tracks?

I have been searching high and low for a while now to find some A Body Bucket seat tracks so I can get my car back together. No luck so far so it looks like I am going to have to spring for the repops from P&G Classics (Only place I can find them).

The problem is they say their seat tracks only fit 70-72 models. I thought all seat tracks were basically the same for 70-74. Are there 3 different styles of bucket seat tracks for Dusters (70-72, 73-74, 75-76) or are they all the same for 70-74?