Well, testing at the moment, for SailfishOS
https://build.merproject.org/package...latest_armv7hl

And how easy would it be to get the Sailfish version onto Fremantle? Surely only minor modifications would need to be made? Or are talking about a complete rework of the commands here?

actually, quite easy, just install this and its dependencies
https://pypi.python.org/pypi/python-onedrive/14.04.3

Is there any chance something could be compiled and put onto the catalogues for use with HAM? Of course once the Sailfish version has been verified and tested as working well.

I would say, that is a great idea. But sure it needs someone with coding skills. I have seen one app for the Windows once that lets you manage many cloud solution like OneDrive, Google Drive, Dropbox and many more. Now I dont recall if it was open source or even available for Linux. But if there is one then there may be many other clients like that which are open-source.

It would be really great if someone makes a client where we could access many cloud solutions simultaneously. And almost everybody uses cloud these days.