If you only brought in $9k last year, and that was a pretty typical year, then you probably don't have any old tax liability. If you really want to be sure, you can do as gjcoran suggests and call the IRS with your EIN. But I would just focus on getting things fixed going forward. You can do one of two things. 1) If you have brought in less than $10k for the last four years, go ahead and file your application for examption and say that. You qualify for the lower application rate of $400.
Or, get incorporated and start a filing as a brand new organization who expects to bring in an average of $10k over the next four years. The new 1023-EZ is very simple to fill out, and then you will have everything straightened out once and for all, and just need to file a postcard return going forward.
If you have an EIN, then you can call the IRS exempt organization line and ask them. They were always friendly when I called them. The agent I got the first time told me that, not only had no 990s been filed, they actually had no record that our EIN had ever been issued (which, she said, was likely because it was issued before they computerized their records).
Sounds exactly like me. I'd really like to eventually leave the PTO in good working order! I definitely don't want to leave someone else with a mess. After all, it's the president's responsibility!