Presently, gzip files are not admitted to Macintosh Garden. It seems, not even tar.gz: I tried uploading .tar.gz, resulting error:

For security reasons, your upload has been renamed to
PowerBook_1400_floppy_set_Mac_OS_7.6.tar_.gz.

The selected file PowerBook_1400_floppy_set_Mac_OS_7.6.tar_.gz could not
be uploaded. Only files with the following extensions are allowed: sit
tar.gz tgz dmg hqx bin cdr iso zip sitx img.

I ask you to accept gzip files, .gz filenames.