These are the 60/40 seats i got from the Bonneville SE/LE.
The red seats are 91/92 Bonneville and the grey buckets are 93up Bonne. They hold you in better and are even more comfortable than what i have now. Although i have never sat in the 91 style seats they seem to fit the style of my car better and the head rests are smaller than the newer ones. I would think the 91/92 seats are capable of swapping the seat brackets too if not at least re-skining the seats as i've done before.
The older thrown pillow look seats , which i really like are too difficult to find in good condition.