BRECKSVILLE: Mike was among old friends.Derf was there goofing around — at one point mugging for a vintage camera in front of an old school bus.And Jeffrey was there, too. Standing along the fringe — quietly hanging out just like in real life.For the past 21 days, actors in 1970s era clothes have been recreating the high school years of Jeffrey Dahmer in and around Northeast Ohio for a film adaptation of writer-artist John “Derf” Backderf’s graphic novel My Friend Dahmer.Michael Kukral, now a geography professor in Indiana, said it has been an eerie experience watching the final scenes being filmed depicting his own teenage years when he, Derf and Dahmer were friends back at Revere High School.“I was back at my own prom,” said Kukral, who is simply referred to as “Mike” in the book and film.Watching actor Ross Lynch, who starred in several popular Disney Channel shows and movies, become Dahmer was particularly disturbing.“He has it down, from the walk to the mannerisms,” Kukral said.