I've read it but don't think I've ever used it - and if I wanted to refer colloquially to the city these days I'd just say "Brum".
Independent, The (London), Nov 6, 2000 by CHRISTOPHER HAWTREE
THE NEW edition of Richard Cook and Brian Morton's hefty, seductively erudite Penguin Guide to Jazz on CD stopped a morning's work, and one learned, apropos Theo Travis, "Brummagen used to be
the cant for anything shoddily built, ersatz or second-hand but there is nothing but cleanly smelted strength and quality in the work of this Birmingham-born saxophonist."
Seventeenth century in origin, it first referred to counterfeit groats."http://findarticles.com/p/articles/mi_qn4158/...
my bold _used to be_ certainly dated, now obs.?
Useless pice of trivia - did you know that Frankfurt holds a Christmas Market in Brum every year?http://ezinearticles.com/?Birmingham-or-Brum...http://www.birmingham.gov.uk/GenerateContent?...