Good point. One can't find a 635mm (700B) wheelset anywhere, so the old steel wheelset has to be taken to a wheelbuilder to have a custom rebuild done. My LBS mechanic had to relace my Pashley 635mm wheelset as it used an unusual lacing arrangement. It can be done. As for drum brakes, they are cable actuated on my Raleigh Superbe and Pashley Roadster. The rod brake linkage can be removed from the frame for a clean look. Cable is more readily availableand can use modern housing sealed from the weather. If you're dead set on authenticity, then sure keep it museum-quality. If you just want a bike that has easily replaceable parts, then no one will care that it once looked vintage.