I'm not sure if he still carries them, but you should try Poppy at the Red Shed. I picked up two or three from him a couple years back. They were Cordura and PVC in construction, and VERY reasonably priced. I was very happy when I got them, and they are still in use.
Also, you might try Bob Meiser and/or Steve Godshall. I'm sure they would have something laying around.
I think either of these would land you a tube at a very reasonable price compared to what else is out there.
Have you called Echo or shot a message to the customer service email on their site. They have always been wonderful to work with. I got a rod tube with a bad zipper and they sent me a replacement that arrived within days.
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