Hello, I have been told that FB [Fratelli Brothers] from Berscia were precision engineers and they manufactured hubs, cranksets and headsets for bicycles. During the period 1930-1940 they also manufactured a few frames. These have open rear track ends with axle adjusters and rod brakes. The "old fashioned" decals depict an eagle and the initiials FB. These frames, if no decals are now visible, can be identified if the original hubs are present by a letter R on the hub. These type R hubs were only used on bicycles sold with their own frames and are apparently very rare.