Several options...upgrade the lights to the current generation of LED's. You get awesome lighting and much better optics. You can buy LED replacement bulbs that are plug and play, they will flash/pulse at low speeds but that smooths out some at higher speeds. You can also build a rectifier board to stop the higher speed pulsing. Or build an LED set up to fit the old housings. FWIW Dorcy was low end stuff, the newer generators and lights on the market are much better. I am setting up a bike right now with a wheel driven AXA bottle generator, LED tail light and the B&M Retro Halogen head light.

Aaron