Of course it's not open source, there's no source to even be open or closed yet! It is Creative Commons, though, which is different.

It may be using a CC license, but nothing that's marked NC is meaningfully part of the commons. Yes, some guy can make a part to fix his printer, but that guy can't sell those parts to other people.

The existence of a service manual doesn't mean you can get parts once the company disappears or loses interest.