What diagram built in 1962 has a lot number smaller than 30702?
CREATE TABLE "list_of_preserved_rm_bs" (
  "lot_no" real,
  "diagram" real,
  "built" text,
  "builder" text,
  "fleet_numbers" text
);
SELECT MIN("diagram") FROM "list_of_preserved_rm_bs" WHERE "built"='1962' AND "lot_no"<30702;