Hi Nicola, I am a saw and tool guy. As a previous response suggested you need clearance for the teeth. On a saw like that clearance is obtained by grinding a reverse bevel on the blade, that is to say that the spine of this blade is narrower than the cutting edge. It's probably about a 2 1/2 degree bevel on both sides or 5 degrees inclusive.
The teeth on that saw were ground in with a finely pointed grinding wheel, it could be done on a tool and cutter grinder. Files made for saw filing are triangle files, they have 60 degree angles on them. A similar saw to yours pictured could be made using triangle files but the points would not be quite as acute. The angles in the gullets of your saw appear to be about 30 degrees.
There is lots of information on the web about filing saws, Google "saw filing" and you will get a basic idea of how it can be done. Saw filing is becoming a lost art, not many people doing it these days.
As you seem to have surmised, not very many of the "saws" we see on survival knives these days are actually useful for sawing, the geometry is just not right (it is right in your example) The best one can hope to do with most survival knife saws is worry something in half, it's best to just chop it in half with the cutting edge. But, those saws do look cool on the back of the blade.
Good luck, have fun, Mark