That system uses the points as a trigger only, VERY little current flows. As a result the points can get electrically isolated very easy.
I have seen new points out of the box get this way. I have always assumed it to be oil vapors in the packaging. Try moving the distributor till the points are closed and pull a piece of clean dry paper through them (non glossy paper). After the paper grind the points together with your finger or the tip of a screw driver and try again.
Bosch Master, ASE Master, L1
33 years MB technician