The battleship Missouri, where the Japanese formally surrendered to the Allies ending World War II, is afloat again in Long Beach Harbor after dry-dock refurbishing in a $475-million renovation project. The 58,000-ton, 888-foot-long battleship is scheduled to be recommissioned in the spring of 1986, Navy officials said. Tugboats labored about 1 1/2 hours to move the battle wagon from dry-dock to a pier where work will continue. Two cities, San Francisco and Honolulu, are vying to be designated the nuclear battleship's home port. A recent poll financed by the San Francisco Chamber of Commerce shows 53% of local residents favor stationing the Missouri there, 43% are opposed and the rest are undecided.