Newbie first post. Help ID brackets

[m7vasque]

Hello All,

My neighbor up the street approached me this weekend said he had some bucket seats for sale that would fit my 71 C10 . (Currently have a bench seat in my truck) According to seller he pulled them from his 71 Blazer, had them reupholstered and never re-installed them. Blazer was sold. These seats are just sitting on his patio.

After doing a quick search and comparing pics of other buckets on the site I'm guessing they are actually 73+ buckets from a blazer but MAYBE the brackets are for a 71? so the driver side will fit into my truck (hopefully). I know I'll have to order the fixed passenger side brackets, just more concerned about the driver side.

Attached some pics of the driver side brackets, any info on what year these brackets actually belong to would be greatly appreciated before I possibly buy the seats.