In [1] Fedorcuk, using diamond, proved that there is a hereditarily separable compact space of cardinality $2^{2^\omega}$.To my best knowledge, Kunen created a humanly digestible proof, but he has not published it (and he passed away). Can I find Kunen's proof somewhere? Or do you know any other proof of the theorem of Fedorcuk?

[1] Fedorčuk, V. V. The cardinality of hereditarily separable bicompacta. (Russian) Dokl. Akad. Nauk SSSR 222 (1975), no. 2, 302–305.