Teheuti
Some of this material was covered here back in 2005.
http://www.tarotforum.net/showpost.php?p=549686&postcount=23
http://www.tarotforum.net/showpost.php?p=549686&postcount=23
Thanks for the photo. I love that there is a snake biting its tail around one of the cup stems! I haven't been able to find any example of twin serpents so far - although twin dolphins can be seen on many versions of the 2 of Cups. I'm not sure what he means by an inverted M on some cards - although a case could possibly be made for the chalice decoration on most of the French decks. The M shown in your example of the early Italian deck is formed by the water pouring up and out in two directions and water is Water (also Mem or Mari-sea). Waters of Creation is not a stretch in an Ace.Despite what Mathers says, the GD Ace actually looks like these examples from Kaplan Vol 1.
Aces of Cups
I'm not totally convinced Mathers isn't full of it. He may have actually seen a Spanish Ace with the design he describes, but I believe there's just as good a chance he made the whole thing up, especially the Egyptian part.