Another way (avoids Linux name issues)
Set up Calibre on W7
Share the (created by you) Auto Add folder . This will be the place Your Linux user will drop books to be added.
Use The content server (runs on W7) to retrieve books from Linux (or anywhere with browser access)
Use Remote desktop connection (on W7) and the client on Linux to make Calibre changes (does interfere with concurrent desktop use

)