Help identify brake pads?

I have a '63 Valiant with front disc brake conversion. I need to change the pads but don't know what car the discs are from. Caliper has star stamp, brake pads are two different sizes (one 5 inch and one 6 inch), two-piece caliper is held together with two keeper plates, each with a single bolt. Disc and hub is all one piece.
Can anyone help me identify what car model this is from, and how to go about locating the correct new pads to buy?