Thank you for the answers. The device indeed looks like it'll get the job done. But I wouldn't build it myself without a comfort strap. Also, if I were you, I'd avoid wearing it for a long period of time. The noose strap is known to cause some problems, especially with long term use.
Either way, your detailed post will no doubt help many others in need in the future who are looking for a head start on how to build an extender on their own. Whenever, if ever, someone handy like yourself finds a cheap alternative to the noose strap, such as a comfort strap or a vacextender peice like the one Iguana talks about in
this post.