He says he\’s 61, but you wouldn\’t know it either to look at him or the paper-shrouded desk in his downtown office. After half a life crusading, his batteries retain their charge even as his office space threatens to succumb to the ever-encroaching mudslide of municipal files. I am told that City Councilman Joel Wachs prefers holding forth from his offices in Studio City. But today is a day for meetings and interviews — it is past 3 p.m. and I am his third griller of the afternoon. He is always this busy, even more so now that he is running for mayor, and his desk is always on the verge of collapse. \”I haven\’t taken a day off in 20 months,\” he confides.