I've been making these rod and reel tubes for years. I use green or grey pvc upholstery fabric tubes. What they use to roll fabric on to. They are equivalent to sched 20 and are 54 to 60 inches long.
I cut the tube in half about 4 to 6 inches on one end and saw half of that off to make the reel end.
I line the inside of the tube with light weight nylon fabric, like ripstop tent cloth, and use close cell foam in the tip end. I then sew a cordura sock with a zippered reel pocket and slide it on to be sure it fits. If it's right, I spray some fabric glue on the tip end of the tube, pull the cloth over the pvc to just before the end, then spray glue on the end and finish by pulling the reel pocket over the end.
If you sew they are easy. I also make just the tubes and cover them and carry the reels in a pouch made from 3 or 4 inch pvc cut 2 inches long.
Oh yeah, I'm a retired upholsterer and canvas fabricator. Jim
I'm either going to, coming from or thinking about fishing. Jim