Here is another with some potential. These are from water filter cannisters where I work. Every couple of months the change them and one is on every drinking fountain, ice maker, coffe machines etc. They are aluminum, 3" dia and approx 14" long with one end closed and ~.050 thick
The bad part is they have some kind of plastic lining that can be a pain to get out

Aluminum tubing this size isnt to expensive but every little bit helps.

If someone has access to some type of CNC machining getting the flanges or any other ends/fittings made would be nice. I can bend the tubing and weld everything and I even have a lathe/mill setup, but making the flanges is time consuming for me because everything is done manually.
Adam