Nothing wrong with it being a Motorsport shell, it was just built by Ford so that people could buy a cheaper version of the normal road car & go Rallying. Get the VIN number checked by Ford, they should be able to tell you what it started life as.

If that is the case it would account for why some bits will be similar to the normal road car & others have been swapped, these cars are getting on now, very few will be standard nowadays.