Fiesta ST 150 External dimensions:
length:3921 mm
width:1683 mm
height:1468 mm
wheelbase:2486 mm
front track width:1464 mm
rear track width:1434 mm
ground clearance:140 mm
ST150 Standard Wheel Offset is
52.5mm, which means the hub to hub dimensions are 1569mm
Focus MkII Dimensions
length:4481 mm
width:1839 mm
height:1497 mm
wheelbase:2640 mm
front track width:1535 mm
rear track width:1531 mm
The standard offset for the Mk2 Focus also looks to be around 50mm.
So I'm calling bunk. While the MkII knuckles might fit he stubs, I'm not convinced that they are the correct length base on the front track width differences of about 8cm between the two.
Lukeyson