You ought to be able to find a leather or Cordura case - with a snap, velcro or drawstring closure - that you could re-purpose to protect your Camelbak or seat bag from your tool.

It might not be a perfect fit, but if you're having an issue with the brand new "flask," I wouldn't risk not being able to open it when you really need it. Metal containers get dented and misaligned and harder to open as they get older. Grease and wax not only dry out over time, they tend to migrate, so that they either go away entirely, or make your gripping surface slippery, defeating the purpose.