Hi jendubois.
Welcome to our Mattress Forum! 
First off a little word of caution if you are trying to replicate the feel of the Savvy mattress… the risk of getting your mattress just right is much higher unless of course all the components, layers, and design or your DIY “build” is an exact replica and matches in every way the mattress you have tested or slept on (in effect resulting is the same mattress). “Replicating” a mattress component by component in view of a DIY mattress based only on “specs” without the specific guidance of a manufacturer/retailer that is familiar with your reference mattress and materials is unreliable If you are looking only for something in the range of your needs and preferences this can work but you most likely will have a different result because not all components are not the same.
The “target” with these types of choices is generally how closely a consumer believes one mattress will match the one that they are building which is often very inaccurate, this is why I always suggest that those who take on a DIY mattress replication project work closely with a manufacturer who is familiar with all the components of the “blueprint” mattress.
As far as I know, SOL still sources their latex from Latex Green in Shri Lanka ( For comparison this is the same source that Naturally Nestled uses for their Dunlop Latex)
I am not sure why they would advertise the 34 ILD as medium with a 4.7 lb/ft3 (not “square foot”) something is off here.
See this conversion I put together for Latex Green’s Dunlop. The calculations are base on the midpoint ILD
https://uploads.mattressunderground.com/outside/66/2021LATEXGREEN~ILD&DensitiesCalculations.jpg
Here is also a screenshot of the Latex Green’s Dunlop latex densities as listed on their site.
Sleep EZ has multiple suppliers for their Dunlop so to find out for sure you’d need to call or to ask them a question on our forum in SleepEZ’s dedicated expert forum on our site. They are extremely consumer-centric and would be happy to help in any way they can.
As you already noticed relying only on the ILD of the layers or other more basic specs can be very misleading and inaccurate, because ILDs by themselves of any design-specific properties, response, or factors that can make a significant difference in how a mattress feels and performs. On top of this
The answers to your questions about ILD may be a little bit more complex than you hoped, so if you’d like to dive in a little deeper you can peruse the topic titled Likelihood same Dunlop product is labeled differently (by ILD and “firmness”).
I would also keep in mind that ILD is only one of several variables or “specs” that will determine how soft or firm an individual layer or a mattress “as a whole” will feel to different people (see post #4 here). In addition to this the ILD of different materials or different types and blends of latex also aren’t always directly comparable to each other (see post #6 here) so using the ILD of a particular layer or combination of layers as a reliable indication of how firm a mattress may feel to you compared to another mattress with a different combination of layers can sometimes be more misleading than helpful.
Phoenix