I think your wires come from the curb side, so I'd remove the can for the light on both sides and check all the connections, because if a wire is broken on the passanger rear tail light it very well could not allow it to work on the street side rear and top. Of course as Brian pointed out, double check all bulbs etc and clean grounds before pulling other things apart. Welcome to the forums as well!
Scott & Megan
VAC LIBRARIAN WBCCI 8671
1963 Safari from the 1963-64 Around the World Caravan