The file sizes that appear in the directory listing of
are correct. Apache is listing those file sizes.
If you download ".gz" files and they are uncompressed after the download, it must be your web browser that is automatically uncompressing them.
In Chrome (and most other browsers), if you right-click on a link and choose "Save As" it should save the compressed file for you, without uncompressing it. If you just click on a link in a web browser instead of right-clicking, it might uncompress it automatically.
Paul Hardy