OK... so I got a bit of 1" tubing. We measured it in the store, and it looked good. The guy gave it to me for a dollar because it came from their scrap pile. But when I got home I realized that what we measured was actually a sort of wrinkled end bit.... that is, it was actually about .85 inches inside diameter, only the end 1/2 inch or so was squished so that it looked like it was .75 inch inside diameter. (The other end was threaded, so we didn't measure it there.) The outside diameter was spot on, though, so I have hope that another trip might get this solved.