i agree with Daz, its not for the RS.
i have a lucas ignition module one somewhere its almost lozonge shaped )about 70x40mm) with 3 or so small electrical connection blades on it. if this is the one your taking about i think it is for the carbed escorts not the RS. confussingly the part is listed as fitting a RS turbo, it had me confused for a while but the instructions say it fits onto the top of the Dizzy!!!!!!! but nothing to fit it to

so it goes in the big box of shit in the garage
d