To drive the coolant (suds) pump a round-belt drive was taken from an extension of the headstock layshaft to a gear pump bolted to the back of the bed; if the assembly has survived - and it has often been replaced by a more effective electric pump - it is not unusual to find the sheet-metal guard missing.
The main motor was mounted on vertical rails, which allowed the belt tension to be quickly and easily set; on some later versions the rails were adjustable sideways, making a change of motor type and size a very simple operation.
On this model the clutch-operating arm projected backwards through the headstock casting and was usually connected to a full-length bar pivoted on a bracket at the tailstock end of the bed. On later models the clutch shaft rose vertically through the headstock casting and was connected to a headstock mounted lever.

Late 1940s to early 1950s L5 carriage - distinguished, amongst other things, by the large-diameter cross-feed handwheel (without the micrometer graduations of the first models), the Harrison name cast into the front surface of the bed and the spring-trigger, made of bronze, on the power-feed engagement lever. In this picture the round-belt drive to the suds pump is visible.
The doubled-walled apron on all model of the L5 employed a push/pull button to select either power sliding or surfacing whist the power feed engagement lever, below the centre of the apron, was spring loaded and could be snapped into and out of engagement even under full load; the design was so simple, effective and easy to use that it was adopted across the entire Harrison range. 
On all models both the top and cross slides were fitted with proper taper gib strips - instead of the cheaper screw-adjustment kind often found on small industrial lathes machines of this age - and the zeroing micrometer dials whilst not big enough, were nonetheless of adequate dimensions for younger eyes.  A "clog-heel" toolpost was fitted as standard but both a 4-way toolpost and, later, a quickset toolholder, were on the options' list; the 4-way toolpost had a clamping bar with a rather-too-small white plastic ball on its end - and it is surprising just how many of these palm-hurting devices have survived unmodified when for a few pence something more comfortable could have been fitted. Unfortunately the cross slide was not, as on the later M Type lathes, of the full-length type; instead a short slide was used with tin inserts (that are frequently damaged on used machines) set above the cross-feed screw at the front and rear to protect it from the wearing effects of swarf. Later models retained the tin sheet at the front but were given a more elegant and robust cast aluminium cover at the rear. In the picture above the long tongue of the rear cover can be seen projecting backwards beyond the back of the saddle. Because the centre height of the original L5 was only 4.5-inches and the machine very heavily built, it was not possible to get sufficient depth in the top slide for a T-slot to be machined. Consequently the toolpost, single or 4-way, was secured by a stud (as in the picture above). When the 5.5-inch centre height L5A was introduced the saddle and cross-slide castings remained unchanged but the thickness of the top slide was increased sufficiently to bring the tool deck up to the right height and allow a T slot be cut - a modification that allowed toolposts and other fittings to be slipped in position much more rapidly.
The full circle, solid handwheels would have delighted today's Heath & Safety fanatics.