The twin chequered flag badge looks like one that was available from car accessory shops to stick on a gear knob. Can't see the motif on the other two badges. My guess is they were made up and the S & F were the previous owners' initials.
thanks for trying guys. It´s not the previous owners´s initials and I
don´t see any symboical meaning with the barchettas so it´s be removed
and the sweet BARCHETTA logo will replace it.