[30Murray]

I installed one of Tom's EVR's about 5 years ago and it has been working well ever since, but I did have some initial problems with it. Looking back on past correspondence with him, these were the major problems.
First, it was a very tight fit and I had to file the edge of the circuit board so the heat sink would clear the commutator. There is a lip on the generator end plate that it fits against.
Second, it shorted out because the insulation on the backside of the circuit board was too thin - I added extra insulating varnish plus a thin rubber pad. The attached image is the backside before the extra varnish was applied.
It is held in place by a single screw which could come loose and allow it to rotate and possibly rub on the commutator or short out if the insulation is damaged - this hasn't happened to me since I installed it, but it's something to check.