Name the least points with chassis of kurtis kraft 3000 and year before 1951
CREATE TABLE "complete_formula_one_world_championship_" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);
SELECT MIN("points") FROM "complete_formula_one_world_championship_" WHERE "chassis"='kurtis kraft 3000' AND "year"<1951;