buckets original to my 74 sport?

If you don't have the build sheet or fender tag, a sure fire way to tell if it came with buckets is to remove the carpet and look at the floor where the seats mount.
There will be 4 holes in the floor on each side with 2 plates (with holes drilled through them) welded to each side on the holes closest to the transmission tunnel.
The holes where the bench seat mounts are near the door sills on some peaks in the floor pan there, and they will have body plugs in these holes.
See pics, the red one is a '75 and the green one is a '74......