Kugelstossen
So would the mechanical engineering undergrad be considered a quant type background then? From everyone's advice here it seems wise to do the retake regardless and Im gearing up again to score better, I'm just curious if my undergrad and the course I had to take to get through it (differential equations, multi variable calc, particle engineering in one semester) provide a little bit of a hedge for me?
I think your background will certainly help. There's evidence of your numeracy and while a better quant would help, you don't appear to be in the league of those who *must* have a high quant score to be competitive in the process.
I feel insistent on the fact that you should not be chasing rainbows with the GMAT when you soon need to turn your full attention to the applications. If you are planning to apply to five schools, which I recommend, it's important to be doing some introspection around yourself, your career goals and schools that best fit with those.
I hate watching my clients obsess over the GMAT when they would be much better served focusing on what is controllable earlier in the process - resume, the essays, online application, coaching recommenders. Creating a distinct and memorable value proposition that will have impact and be memorable. This evolves over time and slapping crap together a month before deadlines is a sure recipe for self-sabotage and ding city.
So if you have some momentum, I would retake the test ASAP BUT put a period on it by the end of October and do not look back. You should be doing the research stuff right now while studying, and putting ALL your attention on the applications no later than a month from today.