I am another who missed that programme. I wonder if the era was established during the episode?
Here is a Youtube link to the programme. I'll have an enjoyable time watching. https://www.youtube.com/watch?v=H-AzyDvcQIc
Edit: I noticed that the link is not working despite copying and pasting the link. To find the item I searched under "Time Team Buckingham Palace" It was the first in the list.