I had the brake caliper rebuild from a local shop. I notice that the rear brake piston hasn't the typical cut off design. There is only a slight signs of the cut off. It is possible that after 50 years of usage the piston have worn out so much? I attache some photos. Thanks.
During frame-off restoration of my 2600 touring Spider I remanufactured the brake Pistons and have some sets left.
They fit at least all 2600 models (Berlina, Sprint, Spider, Osi, Zagato), but probably other models using the same girling Brakes.
I can send pics by email.
Open to offers...