Timelord
I don't think anyone in the modern RAF will know much about astro navigation, and this is such an obscure corner of RAF history that I doubt the museum will know much either . But if you want to know more - here goes
Without commenting on the knowledge of those in today's RAF you should know that in the fully amended and up to date version of the RAF Flying Manual AP3456 the whole of Part 3 of Volume 7 is devoted to Astro Navigation and Part 3 is itself divided into three sections dealing with the topic.