I don't need much to start. I want to get some 1/2" thin wall tubing to increase the base size of some brass that needs to be in the 0.505" range. The brass would have to be thin-wall (~0.010") to work. If such a beast as thin-wall 33/64" existed, I'd have use for it too. If it works, I'd still only need a few feet of it.
A Hobby Store would make sense, but I tried "Michael's" in London and they didn't even know what I was talking about. Hence the question.