10" brakes on formula S cars?

a question for anybody with an original 65 or 66 formula S car does it have 10" brakes on it?

Thanks for any responses. The reason I ask is I have a 65 Valiant 2nd owner have owned it since 1971 it has a hi-po 273 4-speed and has 10" brakes on it. Have always claimed its basically a formula S Valiant but have never seen another one like it.

Any responses appreciated.
Kevan