Looks nice and clean ! Looks like you finally managed to do your lightmapping correctly 
I decide to give another try to the Salk Institute from Evermotion training vol.1.
Spent 5 hours detaching objects to have a reasonable amount of geometry per lightmap. Unwrapping everything took 5 mins. I have 1900-2000 static meshes in unreal right now lol. Changing lightmaps resolution per mesh is gonna be fun (not).
Check it out , w.i.p and that’s with lightmaps of 128 for each of the 1900-2000 meshes (for testing)
http://littlstar.com/photos/aa43772c
You can see lighting artifact and materials are just a plain texture on this preview.