Lovely pieces of kit, David. They look so... professional!
As I'm attempting a 'less professional' version for manual operation, I'd be really interested to know whether, in practice, you've found the 6mm holes (through which the brass tubes/wires reach up to the point blades) to be 'just about right', and give you the leeway to make fine adjustments at the server end. Maybe it's the recognised 'norm', I don't know. (My version is for peco points, less their spring mechanism, so only one hole needed)
Thanks for your help... and inspiration