I worked for WCOL-FM as an oldies station, and with WCOL-AM as Kool Gold. Sorry...but there's no music format, even oldies that will work on that station anymore.
50's music will get you an audience, maybe even a one share in the ratings...but no advertisers. (The listeners are too old...sorry.) Same for early 60's. The CBS-FM style of Classic Hits might work in Columbus, but not on AM. And the 1230 signal doesn't cover near enough ground anymore, especially at night.
And, sadly...I hate to truth you here...but playing back "the heyday" of WCOL-AM will reach largely only people over 50...mostly over 60 or more. Few will advertise on this type of station. And most people under 50...don't care a whit about the "Legendary 1230".
To succeed with the advertisers, you must be able to get 25-54, with the "tight target" of 35-54 adults, leaned female. Not enough women in this age group even bother to listen AM...and few men will put up with the static.
It hurts me to say these things...I have great respect for what WCOL was back then. But, its time has passed. Let it be.
Remember...Clear Channel tried it once. It didn't bring advertisers.