Not able to open old pages files

Hi all,

There are some old .pages files in my system that I had created around a year back. When I double click on them, nothing happens. When I right click on the files and open them with pages(default), nothing happens. When I open pages first and then try to open the files from inside pages, once again, nothing happens. I had never compressed these files and they have always been stored on either my system's internal hard disk or my backup external hard disk. The documents are not locked and the permissions on the document are ME: read & write, Staff: read-only, and Everyone: read-only.

Strangely, I don't get the preview of the files either when I press option+space and the system doesn't allow me to change their names either. Also, when I created a copy of any of those files, the copy had a size of 170-180 bytes as against the original file size of 700-800 Kb. Also, strangely, when I press cmd+option+i, I see a mismatch in size; for example, for one of the files (117 Kb), I see Size: 1,17,310 bytes (4 KB on disk). What does that mean? Why is only 4 KB on the disk and where is the rest of it?

I tried opening the files in safe mode but it didn't work either, and also tried to open them using the cloud version of pages. Also, I tried to convert one of the files (as an experiment) to .doc format but none of the online converters recognised that file either. Can anyone help me open the files? They are sort of important for me. I am using Pages version 10.2 (7028.0.88) on MacOS Catalina version 10.15.7 (19H2).