If you are capable of building a rectifier then you should be capable of finding a good spot to hide it. Most restored British bikes are converted to modern voltage regulators. We just hide them away ( they’re very small ) . Mine has all the stock electrical system in place, but also a modern regulator under the seat, doing the work. We do this because it does a better job of keeping the battery in good charge, which in turn makes the lights brighter . The electrical systems on old bikes can use all the help they can get. Convert to LED bulbs to reduce the strain on the system as well as improve lighting.