Shown on SCAtoday.net was an article about a blog. This blog covered blackwork of many shapes and countries.
This blog is called Practical Blackwork. There is also a free stuff page where many pdfs can be downloaded, including a Coptic design.
This design was taken from the Antique Pattern Library, specifically a book (in two volumes) from Therese de Dillmont called “Motifs de Broderie copte”. They are located in the embroidery section.
They have great pictures which could easily be charted but I don’t speak French and I can’t muddle through enough to find a date. If anyone can read French, then I wish they could help with the translation!