I connect mine to the basement sink and just let it siphon the water out so I have no need for that part. But I can think of two ways add it.
First is to just take the part from the Python and whittle it down enough to fit in my DIY model. Second is to find a brass washer to fit in the top of the DIY model and then solder a tiny brass tube through the center hole of the washer that is the length of Python part. The tubing should be available at any hobby shop.