
First thing was to provide an outlet for the beer line: -


Testing with water showed that constrained in the box, the polypin still holds just under 4 gallons. Tricky to fit in the ice packs when it's full, though


In position to dispense with the lid closed: -

And a shot showing the whole set-up:

The beauty of this set up is that you can fill the pin while it's inside the cooler in an upright position, and it can be carried around easily. Once the beer line's connected the cooler is put onto its side for dispensing.