This is a very good W & G video which explains threading and how to remove the chain stitch from the machine so it stays locked. Gibbs was a genius IMHO. I can't wait to sew on it.
https://www.youtube.com/watch?v=gjKG9pdacv0
You have probably already seen this.
Anyone have a little wrench I can purchase. It did not come with anything but what you see in the photo, so I am also looking for a manual.