First post so be gentle.
I'm building up a 1946 Maclean’s road frame and have pretty much sourced everything bar the stem, bars and brakes. I've tried to keep everything period correct but am not sure what brakes I should be looking for, any help you can provide in letting me know what brakes would be period correct would be great.
Burlite, B&T Manx, CLB, Doherty, GB, Lytalloy (1947 on), MAFAC (a little later) and Universal(Mod 39) is another, these are examples of brakes makers listed in the contemporary cycling catalogues, although they're not commonly available today (perhaps with the exception of MAFAC).
If you want to keep it British you'll need a GB bar and stem too.
Co-founder of a V-CC section, member South Eastern Road Club and owner of - 2005 Bianchi Reparto Corse (modern), 1985 Raleigh SBDU Pro Super, 1984 Raleigh LU Corsa, 1980 Allin Stan Butler Special, 1978 Ron Cooper, 1975 Bill Philbrook tourer, 2 x very early Roberts (mid/late 1960s), 1966 Raleigh Superbe Roadster, 1964 Allin Stan Butler Special Belgique, 1951 Hobbs of Barbican S/C, 1950 Hobbs of Barbican S/C, 1947 Hetchins Super Special, 1908 Centaur Featherweight. 1988 Specialized Stumpjumper.