You made me go and look
Not easy, but i have a spare zexel, which i took a couple of pictures of. Look at how the wheel looks at the side pointing away from the pump itself, it's all black, then look at the wheel in the picture from the engine bay, there's a shiny spring on the side of the sanden pump, amazingly i succeded it focusing on the right part in my first shot.
I hope this helps you. My zexel pump went after 140.000km, no warrenty left.
Zexel
Zexel
Sanden