Try a surplus store to see if they have any GI issue fuel nozzles. I can't say what we called em, something about a donkey richard?

Anyhow, they fit a bunch of 5 gal cans, little leakage, can be turned upside down, drain fast. They are aluminum or stainless, least they didn't rust, and could be angled even tho they are metal. All mil vehicles had at least one onboard as standard equipment.