I think you have a competitive profile. Your grades are slightly below the top quartile for the more selective schools on your list (e.g. Wharton), but your GMAT score will give them comfort that you have the intellectual horsepower to handle the MBA coursework. I do agree with you that you should address your lower grades and explain that your grades suffered because you were working while going to school. The schools will take a close look at your transcripts, however, and if it appears that you struggled in business-oriented courses specifically then that will affect your chances.
Entrepreneurial abilities and experiences are valued by the schools on your list, but you will have to work hard in your essays and in interviews to show how you excelled and how you've grown from your experience. As much as schools appreciate young entrepreneurs, they must approach this brand of applicant with a healthy degree of skepticism because an "entrepreneur" is something of an unknown quantity. My point is that you must convey the quality of your professional experience in such a compelling way that you overcome the admissions committees' skepticism. This is a challenge that an applicant from an established, name brand firm doesn't have to overcome. That said, I'm guessing that as a career entrepreneur this won't be the first time you've had to work harder than your counterparts who are collecting a steady paycheck. Congratulations on following your own path!
One last thing, I'll mention is that from my experience, the schools don't receive enough applications from Mexico so that will work in your favor as well.
Best of luck with your applications!
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