One thing you could try is looking at the file extensions from DataSet 10’s Natives so you have fewer to guess from.

The rest of the natives still could be that large but I’ll double check if there are other placeholders.

I have updated the post with a list of 2542 NATIVEs instead of 135 after finding a second placeholder size of 2433 bytes.

I updated the post with the URLs that I have found, and what extensions I have tried. Also you can track updates at https://github.com/yung-megafone/Epstein-Files/issues/4