The more I consider this, the more I think I'll just put new hoses in. Just removes the element of "what if". Even though it's going to be a little difficult, I think it's my best solution.
What I would tell you to change with 100% certainty is the 2x shown at the bottom of your photo. If that is treated, the chemical reaction will eat a hole through your tank in a couple years! Ask me how I know.