I bought this deck months ago, on ebay, because it's quite difficult to find it these days. Designed by R.J. Stewart and illustrated by Miranda Gray in 1988, it is based on the life and prophecies of Merlin as narrated by the medieval historian Geoffrey of Monmouth.
This is a pip deck and hence the presence of numbers and the importance of numerology instead of the suggestive power of images might make it less appealing.
Also it strongly differs from traditional decks. First of all three cards have been renamed: The Guardian (The Devil); The Innocent (The Hierophant) and the Universe (The World); and the order of the Major Arcana is a completely new one, reflecting the universe as conceptualized by Merlin. The 22 Arcana has been divided in seven groups of three cards - Worlds, Wheels, Enlighteners, Liberators, Redeemers, Givers, Sharers - plus the Universe as One Manifest Reality.
To make an example, the first group is formed by The Moon, The Sun, The Star as the three worlds of experience and knowledge.