I have tried both a T19 and a T39 from Clarks and both were grossly oversized. I mean so large that the insert would have had to been sanded on the inside to be able to fit/rotate. I was not going to sand a CAC insert so I bought another crystal.Looks great! It's not a look I have fancied trying but I do keep an eye on GEN Service T39s, which seem to go around a similar price, if not a bit less than the TD39. The TD pricing always surprises me a bit. I know they are 'the best' REP of the original profiles but I bought a GEN blistered service T19 (ok, so a different profile) for ~$100 and a used GEN T19 for ~$100, which do seem much better 'value'. It's why a Sternkreuz for ~$20 seems exceptional, really and Clark's for even less.