Getting in off the waitlist at Stern- proving quant aptitude

I am waitlisted at Stern : 700 GMAT (41 quant, 47 verbal), 5 years work exp, 3.3 undergrad gpa with a relatively weak quant background.
I imagine that if I improved my quant profile, I may look like a better candidate for admission.

Should I retake GMAT? I worry that I may not again score in the 700s. I know 41 is low but I find the quant very difficult.
Should I take online business mathematics courses and show record of completion? Or should I take a real college level math course in NYC this summer- I worry that since these courses aren't over until late June, that I wont have completed grades/certificates to show until after NYU has likely made their decisions on the waitlist.

I recently received a promotion and have attended a few networking events and will continue to network with current Stern students and Alums.
Any ideas?