Thanks John - I did find this - -https://searchengineland.com/5-ways-crawl-staging-server-important-site-changes-go-live-save-seo-241... -
But I haven't had success yet - sure you are right but just trying to figure out if there is anything creative that can be done
As you said the site is not published, I advise you to check the URLs first.
are those URLs SEO friendly or not? (I think this source will help you: http://www.techiflyer.com/blog/kick-starter-seo-tips-for-beginners/11)
avoid Dynamic URLs.
Do optimize images and CSS and JS.