Everything I have read (and some great analysis on here by others), show that Pewters and Durock Light tactiles are the same stem.
Really the only thing that makes Pewters different is the housing composition and the spring weight (58g).
I really like the Pewters, to the point that I have made two boards using them. I was planning on sourcing some more but I think I will try this suggestion:
My biggest turn off about the Light Tactiles is that 65g seems too high for me these days. I have really been enjoying things at either 58g (Pewters) or ~63.5g
This thread also has some interesting talk around how Durock is changing Light and Medium tactiles with their leaf and stem - Opgrey in stock linear switches - #14 by HungerMechanic