Welcome to the list Neil, you have started off on the right foot with that
bike. I would guess it's from 1945 -1950. The Mafac brakes are a later
addition but not too far out of period. Can we have more details of wheel
size, derailleurs and hubs and we can tell you if they are also correct.
Carefull take off all the plastic bits and that bottle cage. Do be careful
of the frame finish and the transfers. Bikes like this in original paint and
transfers are increasingly rare and should be carefully preserved. You can
check the CR archives on how to go about it. Maclean/ Featherweights were
based in The Angel, Islington N.London.
Mark Stevens Evanton Scotland