James , Try G and M tools at Ashington sussex, I have bought a lot tools etc from them over the past 20 years,a good reliable supplier.Currently their website shows several Myford slides, better to pay a bit more for a genuine part than some of the dubious imported items, some imports are ok some are rubbish the snag is trying to find out which are the good ones, at least the Myford parts from the original company are reliable ,square and true.I bought my Myford slide nearly fifty years ago and its still very good.At the time I bought the swivelling slide as the table was larger than the fixed slide,some people do not like the swivelling slide as they say the swivel moves, I was apprentice trained and you use your machines carefully ,so many people are impatient nowadays and expect Bridgeport performance from a small machine.I machined the majority of an Allchin on my Myford with its vertical slide.