If its the same as the one on a Mk3 Cabriolet (which it probably is) then its unlikely you'll get one cos I spent 7 months looking for one on my old cabby after I broke the steam seals on either end.

Is it the part im thinking of, thin black hose with whats called a banjo fixing on one end and a nut on the other?

If so, take your old banjo and nut to a rubber fabrication company and get them to steam seal them on either end of a piece of hose.

I actually managed to find this part from new (altho was told it was last one in country) but the nut was not the same size as what I needed so made it useless.

If its not the part I described then completely ignore what ive written! lol