This was a cash strapped charity, paying more than the windows licence cost just to run backups wasn't an option so free options were required. It's not that free Windows backups aren't available, but most have a blind spot with Windows Server and just won't install or run with a server edition.
For small scale scheduled backups, the Cobain Backup tool just works so well, despite being undeveloped for many years, a big shame but that's just history. A Buffalo Linkstation had been run previously for backups and this was a great offline resource for storing backups and files that weren't used anymore but were kept just in case.
However, Cobain doesn't offer a bare metal restore capability and with the relatively undefended server being vulnerable, this might be important. The most straight forward option here was to use Windows Server Backup, and the main trick was to ignore it's deficiencies....and errors!