Inv. 52752 - dating
Email from Jonathan Betts, responsible for International Chronometer Index (ICI) held at The Royal Observatory (National Maritime Museum), 22/12/06:
"William Langford had premises at 53 Broad Quay, Bristol for most of the 1860s & 70s and was succeeded by his son George at 40 College Green, Bristol. Many of his chronometers were actually made for him by Victor Kullberg of London, one of the finest of the manufacturers of the period. The ICI records that Langford No.1737 was rated here at the Observatory in 1866 and 1867, and that No.1777 was rated here in 1868."
Presumably our example must have been made at about the latter date.