XR4x4RS above has a Sapphire Cosworth bumper and bonnet on his car - that bonnet has the short nose and is found on Sapphires and (I think) diesel models).
Non-Cosworth models don't have the vents on the bonnet, and have different, non-recessed, radiator grills and different bumpers - the ones with foglights have them mounted further down and they don't get silver trims around them.
Sierra hatchbacks mostly have the long-nose bonnet where the front edge continues down between the headlights to meet the raisied section of the filler strip.

(Apologies to whoever for borrowing these pics off Google)