I see a fair number of Apple disks and most start with sector 0 having the letter 'ER' in the first two bytes. Others have a GPT boot sector. They then always have an HFS+ file system.
I have just seen a new variation. It started with a normal ER boot sector. The next sector started, as normal with PM and was the Apple Partition map pointers. The third sector then very unusually pointed to DOS_FAT_32.
First attempt to read the disk with CnW failed, but with a few manual inputs it was possible. Firs I had to set the partition type to be FAT32, and the partition start to be 0x40. After this, the disk read OK with CnW Recovery software. Due to hardware issues (the reason I had the drive in the first place) I could not try the drive on a MAC, so I do not know if a standard MAC would read the drive or not.
A future version of CnW will understand this type of drive automatically.