I'd say your biggest weaknesses are your GMAT and your extracurriculars. Your age is less of an issue for part-time programs. As for whether you should go for part time or executive, I'd say that depends on your goals/situation. It's usually pretty tough to get admissions in a part time program unless you are employed in the US and ideally local to the school (or have the ability to transfer your job near the school) -- is that the case? If you're planning to quit your job and just be a part time student, that would be a tough sell. Part-time programs are better for those who wish to switch careers, whereas executive programs are better suited for those in management or senior management positions who wish to rise to general management/executive levels within their company/field. But I think at this stage, part time makes sense for you, assuming you're already living and working the US.
With a 640 GMAT, I think Booth part time program may be a stretch. Even NYU may be difficult. Tepper is a possibility. It is good that your quant score is so strong (that is weighted more heavily), but it will be difficult to overlook your low overall score. It doesn't seem that retaking the GMAT at this point makes any sense - you've scored quite consistently in the past and you don't want to waste time on that. I might suggest you lower your expectations in terms of what tier program you can get into.
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