Guten Tag!
Can't you use anything from the touring line from Shimano FD-T770/FD-T780? Anything from a VSF Farhradmanufaktur Fahrrad should work right, as they all use a 48T big gear on the front?
http://www.fahrradmanufaktur.de/produkte/expedition/
Did you enjoy Museumsuferfest? I know I did
