another rxjs Observable retry strategy

I've seen a dozen ways to implement retry strategies, and I feel like I'm really close. What I have here doesn't throw an error after takeWhile() completes.

getItems(): Observable<ListItem[]> {
    return this.authHttp.get(URL + '/items')
      .retryWhen(e => 
        e.scan((errorCount, err) => errorCount + 1, 0)
          .takeWhile(errorCount => errorCount < 4)
          .delay(3000))
      .map(this.dataService.extractData)
      .catch(err =>  this.dataService.handleError(err, 'The items could not be retrieved.'))
  }

I've seen some jagged looking code snippets that might get it done. I experimented with inserting a .finally() before the .delay().

Once I get this one solved, I'll want to pass the errorCount back up to my subscription so that I can display something useful. "Retry 1 of 4." Something to let the user know what is going on.