That was my bad, as I misunderstood exactly what was being asked.
Here is an answer to better answer the original question:
Alan Scott and the rest of the Justice Society made a gradual reintroduction into DC's Silver Age.
In FLASH #129, Alan Scott (with other members of the JSA) appears in a very quick flashback as Jay Garrick reminisces about them . They team members aren't physically present, though.
In FLASH #137, the JSA physically appears for the 1st time in the Silver Age (appearing in several pages) where they decide to reform the JSA after having been in retirement.
In JUSTICE LEAGUE OF AMERICA #21-22, the JSA returns as an ongoing part of the DC universe, and it begins their annual team-ups with the JLA.
In SHOWCASE #55, Alan Scott appears in his first solo Silver Age appearance (apart from the JSA), though he is teamed-up with Doctor Fate and Hourman.