Oh boy, that's a stand alone complex. We had the same idea at the same time. I just received mine monday.
I can tell you this scheme is messy. The last element seems to be made of 2 elements (1 plano-convex lens and 1 planar lens), stuck in a single ring. You can find the scheme i found that it seems good.
I've try to figure out how to do, but i've never made optical studies. I google all the informations since then...
All i know is the infiny focal distance is 0.8mm.
I didn't found any information about the matter of this elements (to find out their refraction).
What i will try is to remove the very last element, wich is a planar lens, and replace it by a plano-concave lens, with a focal of -50mm or -75mm. But it can be a fail, it's more a guess than a solid calculation.
And for the moment i have no time to do that.
Anyway, you can remove the last element , and try out with your camera, you will have a decent focal distance, and your pics will be fine.
I still have to make a mount adapter, and the best way for me seems to be this :https://www.thingiverse.com/thing:1289753
you can adapt the biggest file (the diameter is the good one), but you need to remove something like 50mm. I'm the one who have made the d-nex adapter. It's easy for me to modify this file. But, same, i don't have time for the moment.