John, "G.B. Arret half hood with adjuster similar Mafac" is listed in "brake sundries" in 1958+ Sandy Holdsworth's Aids catalogues, but not listed in 1957 and earlier. Since the GB half hood is stated to be similar to Mafac, perhaps you can make do with Mafac half hoods. One source is Bikeville http://www.bikeville.com
Peter ...................................... Peter Brueggeman San Diego Calif USA pbrueggeman(AT)ucsd.edu
"....GB "Superhood" levers ....the half-hoods .. does anyone have any replacement hoods ...John Barry Mechanicsburg, PA, USA"