UPDATE...
I got the information I was seeking, and thought I'd update this thread with it in order to be helpful to other members who may be seeking the same information in the future.
The RKE100FW lock controller is a proprietory unit made by Magnadyne exclusively for Fleetwood. Accordingly, there is no mention of the unit on Magnadyne's web site. It hasn't changed much since Rev. A, which was first produced in 2003. As of this writing, 14 years later, they are up to Rev. F. Unfortunately, there is apparently no external lighted keypad that is compatible with this particular controller.
I called Magnadyne and they gave me the information I was seeking. They have always had very responsive customer service. I also emailed REV Customer Support, and they sent me both a copy of the key fob programming manual (with additional helpful handwritten information); and a copy of of the harness diagram, which corresponds to circuit numbers in their current dash harness diagram.

That information will be extremely helpful, should I decide to swap this controller out for a TriMark controller and lighted keypad in the future. (I'll likely do that before too long, as I really enjoyed that modification in my last Diplomat.

) These two pdf files are attached below.
By the way, this brand new 2017 REV Diplomat is quite a coach. I'm extremely happy with it and glad I upgraded. For anyone interested, there are pictures of it in my first signature link below. It is my opinion that REV Group is trying to do some very good things for both the Fleetwood and the Monaco brands (which, of course, is in all of our best interests).