Here are my files:
https://drive.google.com/drive/folders/10br2m1QDRQqFcQiT0-eLc9zUgP6wvq0K?usp=drive_link
The SKP file says “This does not appear to be a SketchUp model!”
The SKB file when renamed to SKP, says “File not found or invalid”
This is quite urgent.
Any help would be greatly appreciated.
Thanks
The skp file is completely filled with zeros. Cant’ be recovered. 
The skb file is ~20% filled with zeros at its end… perhaps @colin can do some magic…
BTW. the skp file looks exactly the same as in post here:
Are you using cracked version of Sketchup?
No, have been using Office Desktop to make these designs. All the desktops have a licensed version.