I am so sorry it has taken me this long to even reply. For personal reasons, I had to put this project in lower priority and was not able to complete. However, I have reopened the files and see what needed to be done and I have good news and bad news.
The bad news is I started this in Sketchup, and I pretty much got the good'ol Sketchup to the limit of its capabilities. Being unable to create PBR textures within the software got me a bit disillusioned, and left it almost for good. But this is a project of love, really. I know the market for scenery is not like in other platforms but still. I really want to get it done and share it with whoever want to enjoy it.
The good news is that I have ported it to Blender and I'm learning Blender as I go. Now that XP12 is in the horizon, I want to release it before XP13 comes along. The Covid situation allowed me some extra time to revisit the project and I have started working on it again. Still a lot to do, mainly all the ground and vegetation, but I want to wait and see what the XP12 has to offer. New work on the whole military base done in Sketchup still. I find modeling in Sketchup a lot easier and I don't need to learn new skill, once the modeling is done, I'll move it to Blender for texturing and export, the X-Plane plugin for Sketchup does not compare to the one for Blender. So stay put and I hope it doesn't take another decade to complete this baby.