I've only got one pair and both are now non-operational. The first one had the spring loose in the pack on arrival and the second has now come off the pip on the coupling. I've tried fixing them but the spring is, of necessity, so small that I am finding it impossible to do. It may be something to do with my hands not being as steady as they used to be. I can only suppose that the second spring became detached either as I was installing the coupling or in normal use, although it hasn't been used very much as a single coupling isn't much use on it's own!
Either way, I am putting the coupling project on hold to see if the Farish version has a more secure spring fixing. Anyone know when they're likely to be available?