I don't think you will have much luck using the find/replace dialog to find instanced of tracked revisions and exclude non-tracked content.
But it is possible to use a macro to step through all tracked revisions to find specific instances where a character was tracked and accept just those revisions.
Code:
Sub AcceptCharChanges()
Dim aRev As Revision, aChar As String
aChar = vbCr
For Each aRev In ActiveDocument.Revisions
If aRev.Type = wdRevisionInsert Then
If aRev.Range.Text = aChar Then aRev.Accept
End If
Next aRev
aChar = Chr(31)
For Each aRev In ActiveDocument.Revisions
If aRev.Type = wdRevisionInsert Then
If aRev.Range.Text = aChar Then aRev.Accept
End If
Next aRev
End Sub
This does feel like throwing peas at an army tank. If you have tracked 8500 changes across 3000 paragraphs and only want to accept 10-20 instances (to come back to 8480 changes) then I seriously question the point of the cleanup exercise.