I have a very elderly ELF lathe with a small-ish AC motor. The BROOK motor starter packed up although pressing the electromagnetic slider in will run it until released. I'd really like to replace the starter unit with something much more modern which will include a simple speed dial too. RS-components seem to stock some very expensive alternatives but I thought perhaps I could build an alternative. I am a retired research tech with a little electrical/electronic experience and can follow a circuit diagram. Would anyone be willing to advise?