Front seat bracket i.d.

[Hawssie]

I have three sets of front seats. All seem to be for blazers or at least were mounted in them at one time. My first question are these blue high back buckets original? My second question is about these loose seat brackets. They look to be from a Blazer put they are quite different from my other two. Maybe a different year? The other 2 are from 72s. On the loose set of seat brackets it has hook for holding the pass seat down and has a set of springs, I imagine to help lift the seat.. The other mounted sets don't. Also the drivers side is different too. I didnt put a picture up of that yet but the driver side slide lever comes out under the front part of the seat under your legs while the other two that are mounted have the adjustment ever coming out on the side. DO these look to be from out body style Blazers?