I think that the reference to Frederick is a bit of a stretch of interpretation. Sans Souci is quite a common French phrase
http://www.wordnik.com/words/sans-souci
I don't think that the story of the Prince is so hard to understand. Here is the gilded and decorated statue, admired by all, and yet whose heart is of base lead. You could see a connection between the Philosopher's Stone of Alchemy and the search for the Aqua Vitae which would transmute base lead into gold. And are the statue's tears not his 'Aqua Vitae' which while, not transforming him into gold, as that is shown to be the true 'base' metal, but does crack his leaden heart in two.
The first stone he gives away is the ruby, which has a very interesting symbolic meaning in the context of this story:
Angelic
Archangel Raphael is the Archangel for those in need of healing, wholeness, and unity and he is affiliated with the colors green and deep pink.
Keywords:
Spiritual wisdom, health, knowledge, wealth, bliss, transition, change, choices,
Metaphysical Properties:
The energy of Ruby is intense and vivid.
It is the chosen stone of Leaders, Kings and Priests for its ability to guide and help make wise and noble decisions.
It is said that the power of Ruby is in its encouragement to follow your dreams and your bliss, helping you to change your world. Ruby will bring light to the dark places in ones life, bringing a spark of awareness to those places where you might still need work, and giving you the opportunity to clear that path. Ruby also heightens our love for life, giving us motivation and inspiration to choose wisely for ourselves and others.
Eliminates the "Martyr" syndrome, the underlying belief that you are somehow "less than" that sets you up to fail by thinking you need to experience pain and suffering to learn. The Universe has all of infinity at its disposal to teach you, it does not need you to be its whipping boy.
Ruby's wisdom is in teaching you how precious you are. You were handcrafted in Love, and meant to be happy.
For people in recovery, it is said to reduce the time needed for chemicals and toxins to exit the body.
Ruby stimulates the heart Chakra. It helps you to change, and make the transition from the person you are today, to the person you want to be, and you wish to be in your heart.
And this is what the Prince needs - he needs to change from the shallow person he CHOSE to be before when he was alive, and make new better choices based on the concern he shunned before, because it is when we concern ourselves with the lives and suffering of others that we develop compassion and become better human beings.
Then he gives away the two sapphires that make up his eyes - the sapphire symbolises faith, truth, sincerity and wisdom.
Sapphire is a stone of protection and prophetic wisdom, a wondrous crystal that can watch over human destiny. It is believed to promote joy, faith, hope and protection during long journeys. It brings light and peace and opens the mind toward beauty and intuitive understanding. Sapphire stones are thought to be able to maintain the hope needed in order that our deepest desires and dreams will be fulfilled one day.
So again we see a symbolic connection to change, to destiny, to transformation.
Next the Prince gives away his gilding, stripping himself of the last vestiges of all that is falsely admired, revealing his base / true nature - lead.
Gold symbolises wealth, riches, personal power and extravagance. All the things the Prince surrounded himself with during his life and which he now sees the falseness of.
Lead represents the impurities of metals and humans. Some say these are the vexations and troubles which God puts on people to bring them back to repentance. Others say these are just the troubles of life which man has to overcome in order to perfect himself. But as lead burns it burns all of the impurities with it which is why Boethus the Arab called it the water of sulphur. The tribulations of life are metaphoric with lead as they cleanse people of the imperfections they incur.
The Philosopher's Stone was only activated and the process of transmutation completed when sprinkled with lead.
Lead transmutes into mercury when combined with silver. Mercury is the symbol of making ideas real and substantial.
Oscar Wilde, like many of his contemporaries at the time, was deeply involved in the Theosophical and Spiritualist movements in which the study of alchemy would have been de rigeur.
Note - the tales of the swallow all focus around Egypt - the subject of fascination for Freemasons, Theosophists and the ilk.