CREATE TABLE table_203_379 (id DECIMAL, "first issued" TEXT, "design" TEXT, "slogan" TEXT, "serial format" TEXT, "serials issued" TEXT, "notes" TEXT)

when was the first baseplate issued ?
SELECT "first issued" FROM table_203_379 ORDER BY "first issued" LIMIT 1
SELECT "first issued" FROM "table_203_379" ORDER BY "first issued" NULLS FIRST LIMIT 1