Watmough, designed by Wilfred Ambrose Watmough and Seaton McCurdy Findlater of Middsx in 1927.

Their design featured the spark plug located over the exhaust valve.

This design is reported to have been used by Jack French in early 750 club days. The compression ratio was 3.7:1?

Reference The Austin Seven Clubs’ Association Magazine, publication No. 1989A, pages 14-20. Article by Robin Boyce and Andrew Lowe