Tributes to David Letterman, Part 24 of 31: Don Rickles 1983, 2015

To commemorate the 5th anniversary of Dave retiring from late night television (his last show was on May 20, 2015), I've put together a series of "first and last" appearances, the latter paying tributes in their own ways to the last giant of late night (h/t Jason Zinoman).
Part 24. Don Rickles
1. September 26, 1983
2. May 11, 2015
3. May 11, 2015 post-show audience capture
The 2015 guest appearance comes from Andrew Lynch's superb YouTube upload, linked here:    • Видео  

The abbreviated audience clip where Don discusses Dave's legacy after the show had ended comes from twoFIRSTnames's YouTube channel, linked here:    • Don Rickles talks to the audience of ...  

Update: As was pointed out in the comments, I mistakenly wrote "September 26, 1984" for Don's first Late Night appearance. It was indeed the year before.