Found it!

One of the objectives of the trip to London was to have a look at this. It is an 8th century Celtic ornamental boss probably from a reliquary that was found in a chest at our village Parish church early in 20th century. Indications are that is was used as a door knob base until its removal in 19th century. The British Museum archive indicated it was in store but when we requested a viewing we were told it was on display so the first destination this morning was room 41 at the BM to have a look at it.
Then on to the Wellington Arch and then Apsley House before going over to Borough Market for a mooch and lunch.
A chilly walk back through the City and Oxford Street to the hotel to collect our luggage before heading north.