Built in tiny numbers from around 1966 to 1968 these 10-inch and 12-inch lathes were of an almost completely different design to the original L Models, had smooth-faced stands unlike any used by Harrison before and with features that foreshadowed the modern M Series lathes of the 1970s. The 12-inch was the second such size to be made by Harrison - and hence the MK. 2 - but was replaced after only 2 years by the Mk. 3 that used a similar configuration of headstock but a new type of screwcutting and feeds gearbox but with the apron design as used on older L5/L5a/11-inch models. The 10-inch appears to have been discontinued on the introduction of the Mk.3 12-inch. In turn this lathes were superseded by new and rather longer-lived 13 and 15-inch models.
In line with styling and engineering changes to Colchester lathes (made by the same group)  a flat front was used on the headstock with a spring-loaded safety engagement lever for high and low speeds; the gearbox changed for a totally new, square-looking, fully-enclosed "dial-type" type with three control levers ranged in a line along its top edge whilst a raised section at the end of the top slide casting allowed the fitting of a larger micrometer dial. On the 12-inch version only an electrical-control shaft ran beneath and parallel to the power shaft with two control levers, one on the right hand face of the apron and the other just outboard of the screwcutting gearbox. Both lathes were offered with either 24 or 40 inches between centres and with induction-hardened beds as part of the standard specification. supplied as standard.  Bored to pass 1.375 inches the spindle could be supplied with either an L00 or D1-4" Camlock nose fitting to the customer's choice. Three motor option, two single speed and one 2-speed were listed: the single-speed 1.5 h.p. motor gave 34 to 750 r.p.m., the 2 h.p., 45 to 1000 r.p.m. and the 2-speed 3/1.5 h.p. motor a much more useful 16 speeds from 34 to 1500 r.p.m.
If you have one of these lathes the writer would be very interested to hear from you..