Hi, thank-you for the note, the 4 seater was called the "Super Chettah", Saunders could not raise the cast to put that aircraft into production.
Saunders timing for the ST-27 was not that bad, in 1968 De Havilland Canada has their DHC-6 Twin Otter and Beechcraft had their Beech 99 coming off the production lines.