Hi,
inthe scattered references I have come across, much is often written and then given a 'famous' name to justify or lend credulity to it's concepts. Not unlike how the name 'Hermes Trimegustis' was applied to various writings, to give them an air of authenticity.

My baptised name in the Ecclesiastic Gnostic Church is Frater Orpheus. I was taken to this name as being a songsmith/poet/story teller I wished to pay homage to a power in this art art form.

I wonder , have you read the 'Hymns of Orpheus' it will tell you little about Orpheus, but much about Greek Religion of the Athenic/ Hellenistic cultures.

In my studies I have never seen any reproduction of the Orphic egg prior to those created by German metaphysicians of Mideval Europe. But if you wanted to get into this, I believe Joesph Campbell touches a bit on Orpheus, in his varied writings. For my money Campbell has a good handle on how this information can be used effectively.

I think the Orphic egg is one which borrows the name and vitality of the legend of Orpheus and his adventures, and that of the Serpent which was an enigma in it's own as a symbol Life/death....and then uses these to portray an Alchemical operation.....which is where most of Hermetic thought led to by the age of Scientific determinism.
my 2 cents
Fox