Sink leak and resealing

I'm pretty sure I'm gonna go ahead and pull it apart and clean it up as best I can then put it back together. I read it could simply be leaking because the compression ring might not be set tight enough. We will see.
Looks like the flange is missing a bolt. The gaskets probably mucked up as well and worth cleaning but it still won't get a good seal if a bolt is missing. If it's an Insinkerator brand I know they sell flange kits at Home Depot.