Apparently the Constitution was renowned for its peerless punch (try Googling Constitution 32 Bedford Street).
Here's the story on the 1880's redevelopment:
Nos. 31 and 32 Bedford Street
This building was erected in 1885 under a Bedford building lease for eighty years granted to John Clemence of Duke Street, Adelphi, gentleman (elsewhere described as builder). The first occupants of the upper floors (from 1886) were the Institute of Builders (now the Institute of Building), the Central Association of Master Builders of London (later the London Master Builders' Association, and now the London Region of the National Federation of Building Trades Employers) and the Builders' Accident Insurance Company. The last still occupies part of the premises. The ground floor was occupied by Macmillan and Company, publishers, from 1887. It is not known which architect, if any, was employed. (ref. 67) <The joint architects were Charles Jones of Ebury Street and Frank Clemence of Duke Street; the builder (and owner) was John Clemence.>
The red brick and terra-cotta front of this building is elaborately detailed in a florid Flemish Renaissance style. Four storeys high, it is divided by pilasters into two bays, with a large three-light window to each storey above the ground-floor shop front, and it is finished with two scrollsided and pedimented gables
From: 'Bedford Street and Chandos Place Area: Bedford Street', Survey of London: volume 36: Covent Garden (1970), pp. 253-263. URL:
http://www.british-history.ac.uk/report.aspx?compid=46128. Date accessed: 25 November 2007.
http://www.british-history.ac.uk/report.aspx?compid=46128