A short update about what is going on - I am still working on a lot of the assets and environments for the first mission along with some tweaks to the research lab that will serve as the "hub" for missions.
Progress is somewhat slow but keep in mind that just about everything I am making for Site 37 is "from scratch". I have been making models in blender, exporting them over to Substance Painter for texturing, then importing them into Unreal 4. Along the way I make various tweaks and alterations, especially if they don't end up looking as nice as I would want them to in UE4.
For example, here is a relatively easy model: a series pipes that could be rotated and still connected together to make multiple variations:
As you may have guessed, it takes quite a bit of time before a model goes from the design and planning phase into Unreal 4 and even then, it may be altered or completely scrapped if it doesn't end up working with the environment.
Here are some (not all) additional models I have been working on: