I wonder if FitGirl or other repackers using either their own proprietary tools or publicly available ones could compress the dataset linked below down to around 30–31 million bytes, or even less? (archive size only!)
When downloading, take note of one of the FITS files: the correct date in the header (relevant to the SHA-256) is October 27, 2026! (Try it hex editing the file: dss_orion_10arcmin.fits)
The datasets:
https://ferencmolnar01.github.io/cmz/test-files.html