Oh, did you find one of those 24V TO-3 7824's? You know, I played around on the simulator and the below works fine. You can just put the other 40uF cap across the one 200V zener instead and make sure at least 10mA to 15mA is flowing through the zener under full load. I could modify mine and it wouldn't need any more caps except for maybe an extra one or two small .1uF disc caps. .