Hey there my friend,
You have some really GREAT stuff in your profile, dude... stuff that will help you stand out and present yourself as a unique candidate, and if you can land that GMAT as you hope, I think you can do quite well. Let's have a closer look:
PROS: 1. You come from Nigeria. The schools do NOT see a lot of Nigerian candidates 2. You come from a very strong industry 3. You have lots of real leadership 4. AND international experience 5. AND good volunteer work 6. AND you have some business endeavors in your background (love to hear more about these)
CONS: 1 GPA 2. A bit on the older side. 3. Goals.
Since your advantages are your advantages, for the moment we don't need to discuss those tooooooo much... just use them!
Instead let's focus on what you can DO to counteract your disadvantages:
1. GPA - like you wrote, but you should explain this in an optional essay also pointing to your success in your Masters and hopefully also your fantastic GMAT!
) You want to firstly give them the reason why you did less well than you could have, and secondly SHOW that you can do even better (like you did in your Masters)
2. Age - Just put lots of emphasis showing how useful the MBA will be to you, and how useful it will be to you NOW
3. Goals - This one is easiest: change them. Going into finance as a goal first of all makes little sense given your experience, and secondly IMHO it makes your profile more boring. Finance is what EVERYBODY wants to do... but it seems to me like you have a more unique profile, with lots of leadership, with these interesting endeavors, etc.... and I think you want to come up with goals with both a) make sense given your past experience b) are as interesting and unique as you can propose....
So those are some things to think about as you approach your application strategy. Hope this helps you out!