how to recognize 48 trijet dells

hey

i just bought 48 dells , but i am not sure now i got them... the name and the type that are cast on the sides have been sanded away and i am suspicious about them...

problem is, at the top they are 45 mm and at the bottom (now i removed the manifolds they are 48mm)

and they have an extra small tube sticking out (about 45°) and my best guess it is the third jet. is this correct? or are there 45 trijets as well ( i never heard about them).

and since we are on the subject what is the right emulsion tube for dells on a vw?

thanks for helping

( i need to know before i make a big fuss with the seller...)

nicolas