Hi LT.
Welcome to our Mattress Forum.
I’m impressed at your observance to these components! Excellent eye. The D85 is roughly a 36 ILD
Latexco has a history of being a great source for latex as well as being a very progressive and forward thinking company.
Yes, right. A stift mattress core has a uniformly perforated surface. The firmness/density is identical over the entire mattress (as opposed to a zoned mattress). This would be a Talalay type methodology. Latexco definitely does make 100% latex cores and I’d feel safe trusting that the local company is telling you the truth that these components are 100% NR latex.
I personally am unfamiliar with LSK, but you may find this forum topic helpful.
NikkiTMU