Hi Eric,
Have you considered using the Lucas Dynamo? (I asume you have a “Birmingham” model.
Many say (me included) that they are much better than an alternator on a Scott, for although the alternator has a greater output, they create a considerable noise at low revs due to the magnetic reluctance, making the engine sound like you’ve left the big end rollers out. Using the Lucas dynamo with a solid state regulator is probably the ideal.