After sinking to historically dismal lows, the FHA saw a modest rebound in market share early this year and has pinned its hopes for revival on Congress giving it higher loan limits and improved product flexibility. But with no public fanfare, the only FHA program that’s showing any life at all is the agency’s home-equity conversion mortgage – a product that echoes the agency’s long-forgotten role as market innovator. From October 2005 through the middle of August...