The original idea for the water/ice tanks used large diameter fuel caps. They are big enough and readily available. The more I thought about fuel ending up where water should be the less I liked the idea. While a good crew would likely never make this mistake it had a chance and it wasn't sitting well with me. So, while the chassis was out for paint I took the time make a pattern and cast a set of flapper style doors that are clearly marked for ice water. Just need to finish the machining, add a little blue paint and a thumb screw to keep them closed.