The aircraft had not been flown or the engines run in twelve years. Before departing on the accident flight, the pilot and an A&P mechanic inspected the aircraft. Shortly after takeoff, the right engine quit and the left engine began to run rough. The pilot was able to restart the right engine and managed to keep the left engine running by adjusting the mixture. While on downwind for runway 16 at the destination airport, the right engine began to lose power. The pilot elected to land downwind on runway 34. While on final approach to runway 34, the pilot observed an aircraft landing in the opposite direction. At this time, both engines began to lose power and the pilot elected to execute an off-airport landing. The pilot landed in a scrub brush covered, open field. During the landing roll, the aircraft crossed a road and collided with a road marker. The examination of both engines revealed that both engines' fuel control servo and main fuel system screens were dirty and partially plugged. The left engine distributor valve piston was seized and contained remnants of the fuel tank's bladder.