cheers mate, if you get the time, if you unscrew the air cap, underneath is the fluid tip, conical in shape, and the aperture is where you can just see the end of the needle. This is the aperture we're talking about.
I'm so fed up trying to source nitro in this country that isn't in an aerosol, and this stuff appears to be massively more hardwaring anyway, and looking at your pics, the shine is spectacular!