Mortgage Master, a large regional lender, opened shop in Williamsburg in December. The Massachusetts-based firm is among the largest, privately-owned mortgage lenders in the country with over $5 billion in loans a year and offices throughout the northeast and in California. Apparently the skyrocketing market in Williamsburg has caught its eye. The 1,600 square-foot office — a bit off the beaten path at 697 Lorimer between the BQE and McCarren Park — is staffed by Brooklyn locals. The landlord installed reclaimed timber, an old winch and other odds and ends found in a building he owns in Greenpoint. More pics after the jump.