scratchm: The save files are located at C:\Users\YourUserNameHere\AppData\Local\Obduction\Saved
This and a bunch of other random info is available on the cyan support knowledge base at
support.cyan.com/kb.php
That's definitely where they are supposed to be. i"ve since figured out that Microsoft, in its infinite wisdom, created a hidden duplicate Admin User in a folder called Migrated default, which was invisible. I'm guessing it occurred when I updated Win 8 to Win 10. I don't have a "c" drive, it's called BootCamp. But I found the wayward user folder when I searched the disk with the "show hidden" setting.
Something else I discovered; You CAN save sequential game stages, in the "Load Game" panel. But you cannot name them inside the game interface. It automatically creates a numbered save file with the name of the World.
In the finder (or whatever it's called in windows) create your own archive folder outside of Obduction's save folder and copy your save folders and then rename them.
Thanks, SCRATCHM