I had one made up and the banjo has a score on it meaning it's never been 100% oil tight I'm quite happy to get an unbranded one as the ones in the usual places seem bloody pricey Any idea what it's from?
Go to a proper hydraulic place Rob, shouldn't be expensive. The one I use PPS (chesterfield) even sell doughty washers for peanuts which might fix your problem more easily than a specific thread banjo bolt?