Jan Peter,
lots of people on here are using contact-less ignition modules. I have a reproduction Tach from Vintage Speedsters and I am using a CB Performance "Magna Spark", others use Pertronix modules and still others use different modules.
I have not read of anyone using mechanical point contacts (and I think few people now remember how to set them properly!), but there are still maybe a few people out there who have not changed.
All of these seem to work OK with Chinese reproductions of VDO Tachs, but, honestly, you can never tell until you get the module and try it out. Usually, if it grounds (earths?) that side of the coil enough to fire the spark it will also work with your tach.