I have found it at last necessary to switch to a non-original Blogger site design. While out of choice I would have preferred to keep the same template as the blog had previously, I found that with the recent changes to YouTube videos, they could be better exploited with a wider design.
This change will allow me to embed larger videos, and will also stop widescreen videos from breaking the site design, as was happening with the previous template.
This new template - at least at the moment - is pretty sparse and simple. Whether that is an advantage or not is up to you, but I'll be doing my best to readd some of the features of the old template (and possibly some new ones!).