Graphics direct do genuine spare parts including nozzles and needles for Sparmax but looking at the prices it actually may make sense to get a new airbrush if you can afford it?
https://www.graphicsdirect.co.uk/pages/search-results?q=sparmax+sp+35+spare+parts
As for your problem - I'm not familiar with the sp35 I assume there is a circular nut holding the needle in place - can this be loosened so the needle can be slid forward?
Needle is 0.35mm btw.
https://www.graphicsdirect.co.uk/products/sparmax-sp35-double-action-airbrush?gclid=CjwKCAjw9uKIBhA8EiwAYPUS3OZgThK-xxe_g5sO9JUUeZjguIrn7Innfau5C6uJTmjeBst2-832dxoCq2kQAvD_BwE
Chris Hopper