Thanks for the advice I’ve been in contact with the suppliers unfortunately they don't stock them but can get them from America taking few weeks for delivery. The reason I damaged the seal was because it was letting paint through but I tightened it up too much so the needle wouldn't go through it, I them released it off again but when I began to use it that’s when the problems began the paint was pulsing, I then tried the bigger needle in with the same result, I've been messing with it again today with very fine adjustments with a positive result NO more pulsing, I’m still going to order one from the States and keep it as a spare, because unfortunately I can't help myself but mess with things I no nothing about, at least now I know not to over tighten the seal. On the plus side no more paint passes through the needle seal.
Message for Beanpoleuk
This is my first airbrush I've only been practicing but yes even with my skills you can get very fine lines with it, I use spectra tex paint which runs smooth through the gun, If you post a thread on this forum there are a lot of experienced people on here that would give you some sound advice.