The beginning of the marque — the Turnham Sports first raced in 1967 at Baskerville in Tasmania.
Turnham Sports Cars started about 1966. The name is the part combining of Peter Turnbull and Tony Hamilton's last names. The first Turnham was the Turnham Sports (52 below) and the most recent is one of the many Turnham Clubmans (1 below).
This site outlines the history of the cars.