I think we are stretching our definition of "70s" tunes a bit here ... the Clarence Carter track is from '85, I have the UK 45 on Certain, and the Sidney Barnes is one of those Motorcity recordings, so probably from the early '90s.

That Decisions tune is great and got repromoted by A&M in late '72, though it looks like it was the ballad on the other side they were plugging. Pete Warner is a great Patrick Adams production.
Here are a few goodies from mid '70s Chicago ....
The Natural Four ...
The Notations ...
The ever wonderful Tyrone Davis ... not sure whether this one was ever fully appreciated but personally I love it ...
And one that keeps popping up all over the place by The Impressions ...

Roger