if your contact points are pitting that means that the capacitor is bad or the ignition coil is very low impedance requiring more amps to fire. Use a denso 0.47u cap that you can buy anywhere because you wont be able to find a new bosch one so easily. and make sure all connections are clean, the dwell angle should be correct too, its 0.40mm measured between the contact points with the dissy cam at its highest point on the points heel.
but being a VW owner you should keep a small flat b4stard in your toolkit and something that is 0.40mm thick to adjust the points if ever needed. Do a thorough cleanup of the carburettor and ensure all air passages are squeaky clean.
Misfire also occurs due to bad valve clearances. you might want to look into that too
