[Newbies] Tracking down an obsolete class from a RefactoringBrowser / ClassOrganizer

I have been experimenting with some metaprogramming, which left a ton of obsolete classes. Have been able to cure most of them, except for this last one. Pointer Finder shows:

#EventManager -> EventManager class classPool: Dictionary #ActionMaps -> WeakIdentityKeyDictionary a RefactoringBrowser -> IdentityDictionary #getCompletionController -> MessageSend receiver: ECController model: RefactoringBrowser classOrganizer: subject: AnObsoleteEvoPolygonMorph class

So there appears to be a RefactoringBrowser which has classList nil, selectedEnvironment nil, etc, but which has classOrganizer with subject AnObsoleteEvoPolygonMorph.

Is there a safe way to tidy this up please?

...Stan