After a year of looking, the Federal Housing Finance Agency announced last week it has finally picked a chief executive to run the fledgling Common Securitization Solutions: industry veteran David Applegate, who has a long resume in mortgage banking. Applegate led both GMAC Mortgage and GMAC Bank during a 17-year career at General Motors Acceptance Corp He also worked at mortgage insurer Radian Guaranty. Applegate’s last job title was president and chief executive officer of Homeward Residential, Dallas, a mortgage-banking firm.