Much of my FS 2004 Airfield, etc, scenery also works fine in my FSX.
The only problem may be, if you have your FSX scenery maxed, some of the FSX buildings may get in the way!
...but its always worth a try....stick it in your Add-On Scenery Folder...Add it to the library and see what happens....
You can always un-tick it in the library it if it doesn't work successfully!
Nothing to lose...
....!
There are LOADS of excellent FS 2004 scenery which is not available in FSX!
Paul...
...!
Win 8.1 64-bit. DX11. Advent Tower. Intel i7-3770 3.9 GHz 8-core. 8 GB System RAM. AMD Radeon HD 7700 1GB RAM. DVD ROM. 2 Terra Byte SATA Hard Drive. Philips 17" LCD Monitor. Saitek Cyborg X Fly-5 Joystick. ...and a Briggs and Stratton Petrol Lawn Mower.