Gerbes Grand Opening Carnival

Gerbes used to be a large local chain of grocery stores.  Here's pictures of their grand opening:

The trouble is that I don't know which grand opening this is.

They had two stores in Warrensburg.

One store in Knob Noster.

And one store in Holden.

Then Mr. Gerbes died and all of his stores went away.

But that's not really part of this story.  What I'm trying to find out is which Gerbes grand opening is the subject of these photographs.

I noticed that the True magazine had a very distinctive cover that I might be able to trace to a date.

But I couldn't find it online.  Here's another hint. See the guy on the far right below.

When a middle aged man is willing to wear a ridiculous hat in public, he's either desperate for a job or he's the manager of the store.

Does anyone recognize him or remember this event?  Please leave a comment.