After years and years of bickering the Sutton Place co-op at 57th Street is getting close to seeing its private garden atop the FDR turned into a public park. $1 million has already been secured for the transformation and all that needs to happen, according to those involved in negotiations, is for the two parties to settle on a few final issues. Once that's done, the half-acre will quickly go public. And not a moment too soon, the area can certainly use a few more inches of green.