The Roman Britain collection, which I have been working with, was donated to the Museum of Ontario Archaeology in 1950; was excavated from a Blitz crater near the this Mithraeum site. It was originally found on Walbrook Street in 1954.
You can read more about the Roman Britain collection here.
Hopefully the archaeologists working on the project are able to recreate the site to more accurately represent the original temple. I hope to visit it one day!