Graham,
the Honourable Board of Ordnance was disbanded in 1855 and if that box is the original for that scope then the scope should also date from the first half of the 19th century.
The scope has many similarities to Troughton & Simms instruments of the time. The eyepiece shutter and some of the knurling as well as the screws used.
This book might reveal all:
https://www.abebooks.com/first-editi.../1372857790/bd