Cover beans with water, bring to a boil, set aside for an hour. Drain. Add fresh water and simmer until just tender. Drain, reserving bean liquor. Put whole onion and half of salt pork in large bean pot. Mix syrup, mustard and salt with hot liquor to cover beans, top with remaining por. Cover and bake for 6-8 hours at 275°, adding hot bean liquor as needed, to cover beans. Uncover and top with cream for last hour.