Table schema:
CREATE TABLE table_name_51 (built VARCHAR, to_iow VARCHAR, withdrawn VARCHAR, br_sr_no VARCHAR)

Question: What is the number for year built of W27 that was withdrawn in 1967 with a To LoW year earlier than 1926?
SQL: SELECT COUNT(built) FROM table_name_51 WHERE withdrawn = 1967 AND br_sr_no = "w27" AND to_iow < 1926