Sean - The CWR file is the only one you need to keep. Try it, then you'll be sure...
We know there is a bug-fix for that (please try latest SP) to get rid of the files with numerical prefixes. Also, there is a switch in Simulation Options, Default Options, Results tab in the "Results folder" section, that might be turned-on. It is labeled "Keep temporary database files". The bottom-line file you need for viewing results is a kind-of archive file with extension "CWR" (formerly stood for "Cosmos Works Results"). If you give the model to someone, you can send them that CWR file, too. When they open your model and request results, the software will unzip that archive file to expose the results for post-processing. Hope that helps.