This issue has variants.
On-sale date from DC Releases #26.
Note that the ad in Secret Origins (DC, 1986 series) #4 showing the cover of this issue has different artwork than the final comic (Phantom Stranger's head is much bigger and the other characters are in different locations on the cover).
Previous indexer had Niles Caulder (the Chief of the Doom Patrol) instead of Steve Dayton (Mento). Correction and more complete character list from Scott Arthur via the Error Tracker.