Piero
Ciao, I have two sets of brakes shoes, one is from Norton Andover, they are black in color, and the other pair has been relined by Vintage Brake, a company in California. That set of shoes with linings that is a light green in color, with specks of some material in the in the shoes.
I do no think you will be able to tell which would work best, until you identify the material used in making the lining.
Google for Vintage Brake for some good reading on brakes and linings.
Ciao
Mark