CREATE TABLE table_63905 ("Title" TEXT, "Series" TEXT, "Director" TEXT, "Production Num." FLOAT, "Release date" TEXT)

Who was the director of the movie having a release date of 1934-09-15, an MM Series and a production number less than 6494?
SELECT "Director" FROM table_63905 WHERE "Series" = 'mm' AND "Production Num." < '6494' AND "Release date" = '1934-09-15'
SELECT "Director" FROM "table_63905" WHERE "Production Num." < '6494' AND "Release date" = '1934-09-15' AND "Series" = 'mm'