Hi Toni,
I can confirm that using the above interpretation of the DiskSqueeze "extra" header bitmap, the "20" at offset 0xA8 in the Image82.dsq file correctly indicates that Disk Block 959 is full of zeroes in the AUI82.adf image, and the "3D" at offset 0x8E and "80" at 0xA2 in the Image23.dsq file correctly indicate that Disk Blocks 719, 718, 717, 716, 714 and 881, respectively, are full of zeroes in the AUI23.adf image.