CREATE TABLE table_204_309 (id DECIMAL, "model" TEXT, "released" DECIMAL, "usage" TEXT, "features" TEXT, "storage" TEXT)

which was released earlier , mark 1 or distributor ?
SELECT "model" FROM table_204_309 WHERE "model" IN ('mark 1', 'distributor') ORDER BY "released" LIMIT 1
SELECT "model" FROM "table_204_309" WHERE "model" IN ('mark 1', 'distributor') ORDER BY "released" NULLS FIRST LIMIT 1