Recently I was able to acquire my first PBT SA profile key set. It is in uniform R3. I believe this came before SA Ice Caps. This is PBT from Signature Plastics.
Unlike most of the SA key sets that I had, this one is quite unique. It does not come with any shine and its matte finish. Really nice to type on these and I am quite liking it. If its true PBT, I believe this should not produce any shine for a very long time.