The following information is abstracted from A.P. Sharpe's unpublished work "The Banjo Story"

ESSEX & CAMMEYER

In 1893 Clifford Essex and Alfred D. Cammeyer formed a partnership with offices and teaching studios at 59 Piccadilly, London. At first, the banjos and zither-banjos they sold under the brand name of "Essex & Cammeyer" were made for them by Temlett, Weaver, Wilmshurst and Windsor but early in 1896 they opened their own workshops at 13 Greek Street, Soho, and were soon employing fourteen workmen to make banjos and zither-banjos for them. The partnership was dissolved in 1900, when no more "Essex & Cammeyer" instruments were produced. 

CLIFFORD ESSEX

When Clifford Essex dissolved his partnership with Cammeyer in 1900 he formed his own firm at 15a Grafton Street, New Bond Street, London. W. and instruments bearing the name "Clifford Essex Co." were put on the market. At first all the banjos were made for Clifford Essex by Spencer, Weaver, Langham (in London) and Houghton (of Birmingham), but in 1904 he started his own workshops at The Oval, Kensington, with Alfred Dare as foreman. When Richard Spencer died in 1915, Clifford Essex bought his plant and stock and took his key makers into his employ. Although most of the CIifford Essex banjos sold in the early days were made in the Clifford Essex workshops, many were still made by the outside makers; notably Richard Spencer. The Weaver-made banjos were made to Weaver's own design although they were sold with the Clifford Essex label on them. In December 1919 the firm's title was changed to "Clifford Essex & Son" and by then only their cheapest model (The "Popular") was made outside their own work-shops by Houghton of Birmingham. In February 1936 the firm became a private limited company and the title changed to "Clifford Essex & Son Ltd.". 

According to the editor’s notes in the September 1937 issue of BMG, the company had simply outgrown the Grafton Street premises and Clifford Essex had understandably after 37 years made the reluctant decision to move. The other influencing factor was that Bond Street was divorced from the usual haunts of the London professional musician. Apparently, this group of people preferred not to travel very far from the orchestral premises which were situated in Archer Street.

However, Clifford Essex was apparently fortunate to find ideal new premises at 90 Shaftsbury Avenue, W1.  These premises sported 3 display windows and shop with showrooms above. The administrative offices stretched above Nos. 90 to 98.

Soon after the outbreak of World War II the manufacture of banjos (and other instruments) was greatly reduced owing, to shortage of materials and the call-up of workmen. When the firm went into liquidation in 1942 manufacture ceased. The new company, with the title "Clifford Essex  Music Co. Ltd." has made a few 'special' banjos since 1945 and these bear the initials "C.E." in mother-of-pearl inlaid on the peg-head. From the cheapest to the dearest (£3.10.0. to £60) Clifford Essex banjos carried the following model names:

Popular
Clipper
Imperial
C.E. Special
Boudoir Grand
Professional(the only 12 in. hoop model)
Regal
X.X.Special(later called Concert Grand), 
Paravox(an instrument designed on the '”Vegavox" lines with an 11 in. vellum)
Paragon
New Paragon
Paragon Artist
Paragon de Luxe(the last two being gold plated). 

In addition the firm produced three grades of zither-banjo: "Grade III" (the cheapest), "Grade II" and "Grade I”. 

Going therefore by the company trading titles and addresses, the owner of a Clifford Essex Banjo should be able to date his instrument by the table below:

1900 - 1919 CLIFFORD ESSEX & CO 15a Grafton Street
1919 - 1936 CLIFFORD ESSEX & SON 15a Grafton Street

1936 - 1942 CLIFFORD ESSEX & SON LTD 90 Shaftsbury Ave.,
1942 - 1957 CLIFFORD ESSEX MUSIC CO. LTD 8 New Compton St.,
1957 - 1975 CLIFFORD ESSEX MUSIC CO. LTD 20 Earlham Street.