Hi johnk1321,
The specs you listed for the Nutrition are close but not quite correct for the bottom layer which is 36 ILD. You can see the specs of all the PLB Natural mattresses (which use blended Talalay latex) in post #2 here.
You can also read more about the different ways that one mattress can match another one in post #9 here. Every difference between two mattresses can affect how they compare in terms of feel and performance and how close two mattresses that have some small differences between them would depend on your body type, your sleeping positions, and how sensitive you are to smaller differences or where you are in the range between “I can sleep on anything” to “princess and the pea”. I would also read post #15 here and the posts it links to in option 3 before trying to build your own mattress so you have realistic expectations in terms of cost and success.
I would be aware that the firmest Talalay would noirmally be in an ILD range of 40 - 44 ILD (although they did make an ultra firm core to use as a stabilization layer for the PLB mattresses).
The other layers would be similar in terms of ILD and thickness (if you purchase blended Talalay) but the top layer of the PLB is Active Fusion fast response Talalay which will have a slightly different “feel” than the regular Talalay even though the ILD is very close. Some people may be more sensitive to this than others but for most people it would be “close enough”. Finally you will need a stretch knit cover that is very similar to the PLB mattresses because the type of cover you use can have a significant effect on the feel and performance of a mattress.
I think that for most people your design would be “close enough” (assuming you use a similar cover) although there will always be some people that are more sensitive to smaller differences and may not agree.
Phoenix