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Hi James, If you can redirect the pages from the old site that are no longer needed, to the same or similar on the new site, then I would do a 301 redirect. You are still sending users to where they are looking to go and will pass along any rankings to the new pages. In general you don't want 404 pages on your site, so if you have pages that are not relevant on the new site, or if say they are products you do not offer any longer then I would use the GWT URL removal tool and have those pages removed from googles index so they do not come up in search results. Hope that helps.

It doesn't really matter that much if you use the alt text, and title well to describe the image. However, I always recommend (and do it myself) renaming the image to match the title, in your case something like orange-campervan-cornwall-uk.jpg. Always use dashed to separate words, not underscores

Thanks for your help. New to SEO so it's appreciated!

HI James, You can use Screaming Frog to generate your sitemap. If you have more than 500 pages you'll need to buy the license that cost  99 £. -Felipe