That looks great.
Here are some notes that may be of interest.
The Reverse Assembly plot was first published by Phil Goldstein as Seca Rouf, in his booklet CARD TRICKS FOR PEOPLE WHO DON'T DO CARD TRICKS (1974).
Other versions have appeared by Allan Ackerman, Ed Marlo, Dave Solomon, John Mendoza, Jon Racherbaumer, Eugene Castillion and Danny Korem. Other historical details, and routines by Francis Pelkey and Jeff Busby that combine the Progressive Aces, the Ultimate Aces and the Reverse Assembly plots, are contained in issue 8 of Jeff Busby's magazine ARCANE (1982).
I created a version in 1981, Son Of Demonic Messiah, that used red-backed kings and a patter story that could be used here too.
After offering to explain how card cheats palm cards using an invisible sleeve hook, the performer introduces a set of red-backed Kings.
He also has a blue-backed deck of cards. He lays the four Kings out on the table and deals 3 blue-backed cards on each one, explaining that the red-backed Kings will be much easier to follow as the cards are palmed. One by one the Kings vanish and appear in the performer's hand.
"What happens if you're caught cheating?" the performer asks hypothetically. Suddenly the red-backed Kings vanish from the performer's hand and return to their packets.
In 1997, I created an assembly routine with a presentation based on Blackjack (where four bad hands created one good hand as cards transposed). I also experimented with the same combination of gaffs that Keith uses in his routine (as noted in the Jennings routine). I mention this because my routine uses my move Turnantula, a completely angle-proof (and easy) move that allows you to spread the four-card packet face-up, showing an ace on the face. You square the packet, turn it face-down, then turn it face up (using Turnantula) and the ace has vanished.
So take Keiths routine, use Turnantula whenever you need to show a king has vanished or appeared (i.e., whenever you need to secretly reverse a double-face card). A short description of the move appears in ENCHANTMENTS by Wesley James (Hermetic Press 2004, pp. 389-392).
Richard Kaufman has pointed out that parts of the McDonald routine are very similar to Hofzinsers 19TH CENTURY TRICK The Power of Faith in HOFZINSERS CARD CONJURING (Dover 1986, pp. 69-74).
See also the various Deland routines with double-face aces in Walter Gibsons WHATS NEW IN MAGIC and COMPLETE ILLUSTRATED BOOK OF CARD MAGIC. See also: 36 TRICKS WITH FA-KO CARDS by Ronald Haines and FEKE CARD TRICKS By Harry Stanley for more references.
A fabulous history of the four ace assembly can be found in Darwin Ortizs THE ANNOTATED ERDNASE (Magical Publications, 1991, see note 230 at pp. 196-203).
Another excellent historical essay by Jon Racherbaumer (along with an excellent routine) can be found under The Olram Aces in MARLOS MAGAZINE VOLUME 3 (Marlo, 1979, pp. 24-38).
Larry Jennings created a four-ace routine with double-face aces in the leader packet. Apparently Juan Tamirez has also something along these lines. This may be the one referenced in the article, MacJennings Aces (Genii January 1999).