That's a lot of signatures (the maximum I've tried is seven), but the binding looks really tight. Like the long stitches on the covers, and especially the decoration on the covers. Does it have end-papers?
Ha ha, thanks! I don't think it was super complicated--all you do is punch the hole further out instead of right near the spine, and sew it the same way. If you wanted anything more specific than that, I'd probably have to dig out my bookbinding notes from hibernation... but let me know if you do need more specific instructions!