I've just fitted the original pattern silencer to my '79 2 litre which I bought from JK (I think it's also available from VW Heritage). It's a pretty good piece of kit and lined up nicely to the heat exchangers without any fuss once I'd dressed the mating surface to get rid of some weld debris. The problem, however, is the fitting kit; the screws for the tail pipe were all about 10mm too long and needed cutting down to fit. Likewise, four of the six the studs for joining to the heat exchangers were too long but I ended up cutting all six to get a ring spanner on where I could. It's an extra hour of faffing about which you could do without to be honest.