The on page grade helps you ensure you've done everything on that page to help it rank. We have some F grades ranking well, too. But that's mainly because competition is low. There's a lot more to take into consideration, however.
Just a cursory look suggests you should focus on links. When I looked, neither Google nor Bing were showing external links pointing to the domain or the two pages in question. Some work there would pay off tremendously.
Also, you should create a Google Webmasters account and submit a xml-sitemap. When I've done that with a new site in the past, nearly all my pages received an initial crawl very soon after.
Along with the sitemap, you'll want to evaluate your internal linking. You're using navigation to link to your pages internally, but you may also benefit from linking to important pages within the actual content, as well.
One thing the on-page grader does not measure is semantic page structure. You have H2s above H1s. That probably won't hurt you a ton, but my eye kinda starts twitching. 