That's better but still not good. The search engines can see your content but the problem is that it's all lumped into one file. With separate files you can make them more focused on a particular subject. If for example someone types "camper roof fitters" into a search engine then it will look for the most relevant matches for that query. A rival page (and there will be many) that is focused on that subject will preferred by the search engines over one the just briefly mentions it. With separate pages you can concentrate on each part of the camper business and improve your traffic. There is much more to SEO but that's why a single page is a bad idea.