I was so happy to see this tutorial! I just bought my Boye set while it was on sale and had a coupon for 15% off my entire purchase including sale items right after Christmas. The tubing looks like air line tubing for aquariums, haven't dug my spare stuff up to confirm that yet but it looks DARN close. I have read through the posts and notice a lot of people talking about the weed whacker line curling. Soak it in warm water over night and then slowly pull it out of the container, over a rag or towel or face cloth to dry it as you take it out, and it should help to undo some of the natural curling it wants to do. The screws you show in the picture look a little bigger than what the screws on my needle set seem to be but I bet I could easily find them.
Like many of the more recent posters I joined this forum/group just so I could more easily see and comment on this post! Great Idea!