The Verdict: Need More Info
A specific law covers Greek Jews who lost their nationality, and it is stronger than the general rules. Take our Historical Displacement quiz, which works through it.
Article 13 of Law 4018/2011 lets a living person of Jewish origin, born in Greece up to 9 May 1945, who lost Greek nationality in any way, recover it by application to the Greek consul.
Their direct descendants, and the descendants of such a person who died before recovering, can apply for naturalisation as descendants of a Greek citizen under article 10 of the Citizenship Code. There is no deadline and no generation limit in the text.
Which applies depends on whether the person born in Greece before 9 May 1945 is still living.