As I said, I am going to rely on the editorial staff of the official printing of the Nag Hammadi Corpus by Brill, rather than your assertions as to what one or two academics say based on a cursory reading of wikipedia. There will always be an academic willing to take any position, particularly if he can publish something based on it, so citing one academic is not really that persuasive.

Consensus puts Thomas in the early Second Century, and virtually no serious scholars put it after 150 AD.