SJS has bag frames on their site ,
http://www.sjscycles.co.uk/brompton-...qfcfa-prod647/
I also see CARRADICE making a couple Brompton front bags in Carradry welded and the Traditional Canvas construction,
http://www.sjscycles.co.uk/carradice...bag-prod18093/
for a hundred quid less than the current Ortlieb manufactured O bag made for the Brompton company.. .