I would drain and replace all oils, gearbox, chaincase, oil tank, (remove engine sump plug drain oil and replace), and forks. Once refilled, I would pour 1/4 pt of oil down inside the rocker box to re- fill the sump, then kick over without spark plugs until fresh oil is pumped into the tank. You may have trouble with the carbs, so I would remove the float bowls and check for crud New battery, check spark, new fuel and away you go. Check fuel tank for loose rust and remove.
