K Jet fuel system

I've just rebuilt my old V reg which i used to race many years ago, unfortunately the plunger in the fuel distributor was completely siezed. With nothing to lose i stripped it, cleaned it out and put it back together - it ran ok'ish but leaked like a sieve! I have picked up another one from a guy who was converting his 1800cc to carbs but although they looked similar they had different part numbers, in short i cannot get it to run well at all. The part number that was on the car originally is 0 438 100 079 so does anyone out there no of one kicking around? Aternatively does anyone have a matching set of Fuel distributor, airflow meter and fuel warm-up / pressure regulator? Am i correct in saying that the same 'set' may also be present on Scirroco GTI, GLI & GTX models?

My plan is to take the car back to circuit racing later this year - can anyone help?