I'd expect the emco to be using ER collets, these being pretty much standard in Europe. sizes range from ER 11(0-7) ER 16,(-10), ER20(-13) ER25(-16), BASIC size is major diam. of collet.
loads of suppliers list them, going rate in UK seems to be about £8 per single collet(VERTEX quality or eq.)try rotagrip or J&l, both have online catalogues.
Hope this helps,