On badgers needles, they have 2 dots at the top of needle for fine and 1 dot for ultra fine....don't think iwata do that though......silly iwata!Can't tell you which is which from your photo but I can tel you they need a good clean and polish...hehe ;0)
The paacshe Talon needles are identified with grooved rings on the back end of the needle one for the finest .25 two for the .38 and three for the .66 the same goes for the tip and air cap , I don't know if Iwata have a similar system to differentiate the parts (it would make things easier).