No additional lawmakers have signed on to a Senate bill introduced in January to overhaul GSE oversight, but it’s not the fault of trade groups in the mortgage finance industry. The Financial Services Roundtable last month sent out a round of letters to Senators, urging them to cosponsor S.190, the Federal Housing Enterprise Regulatory Reform Act of 2005. The proposal was introduced Jan. 26 and was sponsored by Chuck Hagel, R-NE, and cosponsored by Elizabeth…