My replica Miller dipswitch (from the VOC Spares Co) looks great but I reckon it would fall to pieces if I used it half a dozen times. I guess it is supply and demand but we really do deserve a bit better I think. There is only one person who makes these and, like other Vincent parts he produces, it appears to be "this is it, take it or leave it". I may be being unkind but the technology is already in place to make replicas that look like the originals but outperform them.
Not sure what is meant by original brake light switches. The Miller units only appeared for a very brief period, after which the Lucas items were used. These are freely available through autojumbles and e-bay. I have exactly the same switch on my old Riley, slung under the car, covered in road grime. A simple and efficient part.