Pk 125 ets head gasket

i have just taken the head of  a pk125 ets and to my suprise found a head gasket.i have never seen that on a vespa engine standard .has anyone ever heard of this.Its metal . 

UPDATE- ok i have found out its a dr kit(bore 57mm) using ets original head looks like a race or modified crank and transfers enlarged but still a head gasket ?HELP !