looking for a source of plastic wing tubes for aileron extension wire

You could use Mylar. Roll it up then tape it. Can make almost any size you want.

I do the same with paper ... surprisingly sturdy and very lightweight.

All good ideas, here's one more... I like to use Estes model rocket tubes, they come in different lengths and diameters. Clean and light.

I use jumbo soda straws. Its sounds crazy but they can be taped together for any length and being flexible you can curve them or change the shape to make leads easier to pull.

Wow must be some pretty large straws Flyer! Were do you get them?

I was in a Walmart one day and they had them. They were only few dollars so I tried them on my TF 182 and they worked great. I still have some so I haven't look again recently. The problem with Walmart is things disappear at times.

Dave Platt warbird plans show drinking straws for this reason.

You can also roll up manila folders or a flexible sturdy paper, then CA it together after installing through the holes.

carbon fiber arrow shafts. used towards the trailing edge they add an element of stiffness to the wing's trailing edge root area, where you don't want flex. they come in several different weight ranges and diameters, the lightest is more than enough.

What do those tubes generally run?