Accomplishments - CoS / Strategy / CFO

Thanks to Manager-Tools for lots of terrific guidance over the years!

I'm preparing a resume, and I'm struggling to quantify my accomplishments from my most recent positions.  Over the past 14 months, I have been with a relatively large NGO (~300 staff), first serving as Chief of Staff, then as Founding Director of Strategy/Analysis and CFO.

Given that these roles are so much behind-the-scenes and long-term planning roles, how can I quantify specific accomplishments?  I have not been there long enough to have evidence that models proved effective, strategies yielded the achievement of our objectives, etc.  Should I focus on the success of the overall endeavors?

Thanks!