The ol' pull knob!
Hehe, my first diesel, a 1963 190Dc had the same setup as your car does. Here's the procedure:
1. Turn key all the way to "run" position.
2. Pull glow knob out to the first detent (you will feel resistance).
3. Wait for the element to glow red.
4. Pull knob out all the way to engage starter--make sure that the idle knob is turned to the fully enriched position.
5. Light it off!