CT scan Shows D.R. at belly button and slightly above but none below belly button. Would a TT still be ideal? (Photo)

I tend to rely on physical exam findings and functional concerns to determine the main benefits for DR repair.
Normally you can feel the separation by doing a partial sit up. And if you see a lot of fullness standing up but not when laying down that can be a sign as well.
If you have any issues with lower back pain, urinary incontinence or other "core" weakness related symptoms then DR repair might be able to help those.
A full tummy tuck tends to be much more dramatic in terms to skin removal, final tightness and if you're going to do all of that might as well tighten the muscles as much as appropriate to get those benefits as well.

A full tummy tuck would be recommended if any issues exist above the belly button, therefore for you it would still be recommended.

A full tummy tuck would definitely address the problem. A mini-tummy tuck would not address the problem and may still be noticeable. It is a risk/benefit issue for you. You may be satisfied without a full TT, but won't really know until a good exam is done. Hard to evaluate with just pictures. Hope this helps.