The 8,5" centre height "Wyvern" lathe was manufactured by A. H. Tomblin & Son (later Wyvern Machines Ltd.) of Percey Road, Leicester, England, from the late 1940s until the late 1960s. When the Mk. 1 was replaced by the squarer, more modern-looking Mk. 2 on a full cabinet stand in the late 1950s the early machine became known in the machine-tool trade as the "Torpedo-head Model". The lathe was available in Centre, Copying and Capstan versions and was, for an English lathe of ordinary commercial quality, unusual in enjoying an arrangement usually restricted to much more expensive tool-room lathes of a separate gearbox (called a "sub-headstock" by the makers) mounted in the base of the stand with a drive to headstock spindle by V belts. The  3-step spindle pulley ran in its own set of ball races and so relieved the taper-roller bearing spindle of belt pull and isolated it (and hence the workpiece) from vibrations associated with meshing gears; this design also ensured that the machine had a lower centre of gravity and was generally smoother running and quieter than average. Customers could specify the end of the 2.25-inch bore spindle with either a thread or an American L0 long-nose taper.
The 6-speed, oil-bath speed-change gearbox, and the starting and stopping of the lathe, was controlled by a large lever mounted on the front face of the stand immediately below the headstock.; the lever worked through a Herbert double-friction clutch and it was unnecessary to stop the machine before changing all but the headstock-mounted backgear speeds. The clutch doubled as a brake and the spindle could be brought to rest from high speeds very quickly, even when a heavy job was being turned. The speed-change box was driven by either a single or two-speed 1400 rpm 5 h.p. motor that gave, respectively, a total of  12 speeds from 50 to 860 rpm and 24 speeds from 32 to 960 rpm. The speeds were divided into two sections, faster and slower, with the former coming directly from the "sub-headstock" gearbox and the latter generated by a conventional design of backgear assembly built around the headstock spindle.
The drive from headstock down to the screwcutting and feeds gearbox was through a set of tumble gears running in an oil bath; the box could generate 32 different threads (from 4 to 56 tpi) and drove a separate power shaft to take the sliding and surfacing feeds to the apron. To save wear and tear, and hence maintain its accuracy, the 4 tpi leadscrew was normally left out of mesh and used only for screwcutting; a small lever on the face of the gearbox was used to engage and disengage it. The makers listed additional sets of changewheels, at extra cost, to convert the gearbox to generate metric and other thread pitches.
The apron was of double-wall construction with bronze bushed shafts and a single control to select either the sliding or surfacing feed; a separate lever, protruding from beneath the lower edge of the apron, was used to flick the feeds into and out of engagement.
The raised V bed could be specified in lengths that admitted 3 feet, 5 feet or 6 feet between centres and was available, at extra cost, with a detachable gap section that allowed work up to 28 inches in diameter and 7 inches thick to be mounted on the faceplate. Instead of a conventional hardening process the makers offered hard steel inserts let into the top surface of the bed as a way of making it more suitable for continuous, heavy-duty use in industry.
The tailstock was fitted with a 4 Morse taper barrel and the unit could be locked to the bed by both a quick-action eccentric lever and, for heavy work, a supplementary clamp bolt.
A neat, large-capacity draw-type swarf bin was built into the stand and could be pulled out easily for emptying by the two large handles bolted to its front surface. Supplied with each lathe as standard was a face plate, catch plate, thread dial indicator, two Morse taper centres and a 3-point fixed steady. Weights were 25 cwt for the 36-inch model, 30 cwt for the 60-inch and 32 cwt for the 72-inch.