What diameter disc and what off set(height), it could be a front disc from a lower powered ford used on the rear of the capri.
If you put a disc on a table then put the depth rod of a vernier through a bolt hole and measure to the outside hub face from the table/disc surface this is the easiest way, there's not many discs will go under 13" wheels and be ok with the diameter suitable for the cossie/sierra rear caliper.
The consul classic for example used 241 x 10mm discs with a 28mm height, but your height looks a lot more, the 80-90 escort 1.1 used a 240mm with 58mm height that looks more like it.
I can tell you 100% with the other dimensions though.
tabetha