I remember articals on Sierras and Escort in Classic Ford mag atleast 10 years ago, maybe more. So I am surprised there aren't more of them now they are 10 years older !!
I was going to mention the black paint work but was beat to it !
Apart from the body shell is it otherwise 100% XR2 ie brakes, suspension, loom etc.. If so, I'd say atleast £1500