Reset cloud config?
 

So I accidentally saved over the default controls while steam was set to sync with the could, I'd like to revert it back to default please and there does not appear to be any way to do so.

Any ideas?

try this out:

1) in steam right click CoD and choose properties, find steam cloud sync and disable it.

2) open the CoD folder in your windows user profile area, and delete (or move) all the ini files.

3) start up CoD, setup your controls again and exit - to recreate your files

4) go back into Steam and enable cloud sync for CoD.

this should restore your configs to default (which is stored in program files\steam\steamsapps\...\Cliffs of Dover\). If you overwrote those by mistake, delete them and in steam choose "verify integrity". this will restore the correct files.