I'm just making logical, educated guesses. Feel free to point out my errors.
I know the 3 original towers had to come down. The great thing about the location was the salt water conductivity that 630 enjoyed from that location. Once it was decided to co-located with 900-1400, what purpose did it serve to rebuild the center stick? Plus, what would the value of that spit of land been back then? Cumulus could have sold that real estate for big money!
Now, that lone tower is a lightning rod with lights burnt out more often than not. That has to get expensive, quick. Maybe adding height to the 900-1400 tower, using the WGSA-CA site across the street, or even the Alltel site off Causton Bluff could have been cheaper.
Not criticizing, just pointing out what (appears) to be a lack of foresight.
G