The Orphanage, the city’s first repair-and-sales outfit exclusively for mopeds, was opened three weeks ago by Ryan Due, a member of the Greenpoint moped “gang” the Orphans (so named because they began as “a bunch of disheveled, poor kids living together”). Due and crew have already fixed up eight customers’ bikes, and they’re now selling two good-as-new salvage jobs: a hot-rod-red 1978 JCPenney Swinger II ($2,000) and a 1977 Puch Maxi Sport ($1,299). Cheaper mopeds starting around $800 will be available soon (1138 Manhattan Ave., at Box St., Greenpoint; 718-389-1979).