In the 393 Mb zip file uploaded by Mitsk at Flightsim.to, you will probably find the best MSFS Freeware scenery ever. EGSU Duxford Airfield Complete Edition includes the detailed airport with the realistic airshow side. The author adds that “Every building is represented in fine detail with all signage accurately placed. This edition is Virtual Duxford!“
It’s also possible to find separate packs for simmers who need a lighter version of the scenery, so you can either use the airfield without the airshow area, or add later the airshow add-on as a Free DLC.