Roman author Pliny the Elder penned a “Natural History” about 79 A.D., he described 41 varieties varying in colour, texture, flavour, season and keeping qualities. He mentioned that Crustumian or Volemum (Winter Bon Chrétien) was the nicest variety. He tells us that many of the sorts were called after the countries from which they came, such as the Syrian, the Alexandrian, the Numidian, and the Grecian. Thus he mentions Pira Nardina, a pear with the scent of nard (Spikenard perfume) and the Pira Onynchina, ( Cuisse madame) a pear of the colour of the finger nail, These last are evidently Greek.
The Greeks possessed a pear named Onychinon, for the colour of its skin, which reminded them of the colour of nails or onyx. A type of agate which resemples the luster of pearls. We can see that such a pear is a long way from resembling the cuisse-madame, whose olive green skin changes to brown/red on the side facing the sun. However, some French experts thought they had found this old greek pear, onychinon, Jacques Daléchamp thought this,( Historia generalis plantarum,Vol I, book III, Chap VII From 1586) and after him, Couverchel (Traité des fruits) and Prévost in his (Pomologie)have until now (1867) repeated this belief.
Jean-Baptiste De la Quintinie (1626-1688) the head of the French royal gardens at Versailles, wrote prolifically on pears and devoted a whole chapter to the Winter Bon Chrétien and said it is the same pear as that which the Romans called Crustumium or Volemum.
I have many scions of both the bon chretian and the cuisse madame and the longueville, the last 2 now extinct in france. Is that old enough for you ?