I need a straw purchaser now, I can't get imaginative with the truth now and be believed. I'll pay $100 plus whatever they want for two tanks. I drive scrap copper from our primary products up to Portland every two weeks, and could pick one up then. Please PM me if you can help. The advantage of the tanks is weight, they are relatively light and designed for pressure.
In my business time is money, and paring down shelby or whatever else I can make a tube out of, so that it's light enough, will take lots of time.
It seems to me that the K cylinder is the best compromise for me.