Yes and so would I like to see the original manual, but to date I have not seen a copy of this manual which was replaced by a newer version a shortly after Macintosh shipped, even before 1.1 came out in April. So not many to be had.
As for putting something in the Unknown Disk, my experience was it did indeed disappear like the trash after a restart, but it reappeared in its original location and was not deleted. The nearest I can figure out, is you would drag the files you wanted to copy to it, eject your source disk, insert the copy-to disk and drag the files out of the Unknown Folder and into your copy disk. Basically the unknown folder seems to act as a RAM cache, holding the files in memory until you copy them somewhere else. Of course on a 128K, I doubt it held much before you had to start swapping disks though.
As for putting something in the Unknown Disk, my experience was it did indeed disappear like the trash after a restart, but it reappeared in its original location and was not deleted. The nearest I can figure out, is you would drag the files you wanted to copy to it, eject your source disk, insert the copy-to disk and drag the files out of the Unknown Folder and into your copy disk. Basically the unknown folder seems to act as a RAM cache, holding the files in memory until you copy them somewhere else. Of course on a 128K, I doubt it held much before you had to start swapping disks though.