Where can you get a solid state voltage regulator? I don't know what to look for at Moss Motors or Morgan-Spares. All the Radio Shacks have closed.
http://www.ebay.co.uk/itm/Instrument-Vol...=item58a65435d8 eBay is your friend. I'm pretty sure that the one I used was very similar to this although it's probably ten years since I did it, which shows how successful it was I suppose.