It took me so long to find something that I could actually use to set this work up. Maybe I was just being picky I don't know but I literally spent months scouring second hand stores and came up trumps every time.
In the end I purchased these little tiny milk jugs from a kitchen supply store.
We are using larger items to pour with and always pouring on a try, as that means much less clean up and C can do the clean up himself, especially when we he can pick up the items, such as macaroni, kidney beans and sometimes popping corn (good pincer grip practice too), although that is getting slightly smaller. Eventually we'll progress to rice and sand before tackling wet pouring.
I am led to believe that I should also keep my eye out for pouring implements that have different sized spouts. Which I will do but since I had such a hard time finding these little gems I won't be holding my breath.
The tray is presented very simply, with the jugs ready for him to pour with his right hand into the left jug. I have shown him to swap them around after he has finished pouring to ensure he is always pouring from his right. Obviously the aim with this is build the coordination so that the child can pour effortlessly, wet or dry, independently. An important skill for practical every day life.