During the course of 1967, cabinets for the amplifier sections of the Vox solid state range were made by Heslop and Company Limited of Rayleigh, Essex. See the pictures of surviving labels towards the end of this page.
Heslop, in company with JMI, was a member of the Royston Group of Companies (from at least 1961), and had worked for JMI from early 1964, producing runs of bodies for Vox guitars and later in the year cabinets for certain models of amplifier.
Detail from the frontispiece of "The Beacon", Journal of the Royston Group of Companies, 1967.
In April 1967, Heslop and JMI shared a stand, under the auspices of Royston, at the Ideal Home Exhibition.
Page from the Ideal Home Exhibition catalogue, 1967.
The Royston Industries stand at the Exhibition - in view an AC100, and AC50 Foundation Bass, a new Riviera organ, and Phantom bass and guitar. Slightly incongruously arrayed around is occasional furniture made by Heslop.
Labels have only come to light so far in amplifier cabinets. Whether Heslop also produced the accompanying speaker cabinets is not known. It may be that those were farmed out to Gla-Rev in Hainault.
Early amplifier cabinets were slightly smaller than later ones, as the picture below shows:
In the foreground, the cabinet of Supreme serial number 1058. Behind it an early VSEL Supreme cabinet. The VSEL box is 1/2" wider (the boxes are standing on end in the pic. above). It is also 1/4" taller. The reason: the sides and bottoms of early boxes are constructed of 1/2" thick birch ply. The sides and bottoms of VSEL boxes are 3/4" thick.
Defiant serial no. 1198. Heslop sticker dated 15th May 1967.
Dynamic Bass serial number 1135. Heslop sticker dated 12th May 1967.