Sown below is an interesting early machine, closely resembling the specification of the Mk 2. In comparison with earlier types the iron base casting had a better finish and was lengthened to approximately 141/2 inches to allow an increase in between-centres capacity to 65/8 inches. The tailstock cantilever was reduced and the casting became a two-piece affair with the upper and lower sections clamped to the bed rails by a single Allen bolt. The example shown has both a locking bolt at the back of the carriage and one on the cross slide--the rare type with a small brass plunger driven in by a screw on the tailstock face of the casting. The handwheels, 35-mm in diameter, are relatively thin, with a knurled rim and a locking nut on the end of the feed-screws instead of a screw through the boss - however, the nuts shown in the example illustrated are a later type. The feed-screw threads are normal left-hand thread, so  giving a 'correct-sense' drive to the handwheels.
Other early examples here and a Mk. 2B here