Conclusion: it´s practically impossible to recognize original Siltech cables nowadays ? I bought my Siltech cables 3 pairs interconnects in the very early 90´s so I guess I´m lucky as they all "sound" excellent, no sibilance nor other annoying issues whatsoever, they just reveal more details/nuances. Since then I have not even thought to go back to copper cables and I will certainly not buy Siltech or whatever they may be today.
I also have one pair of Kimber and would like to have another too. I would recommend to go for Kimber.