Table schema:
CREATE TABLE table_name_98 (date VARCHAR, test_debut VARCHAR, position VARCHAR, year VARCHAR)

Question: What date has a Position of back, later than 1964, and a Test debut of 1st rl test v new zealand?
SQL: SELECT date FROM table_name_98 WHERE position = "back" AND year > 1964 AND test_debut = "1st rl test v new zealand"