Life-Long was a Mentmore trading style, although Conway Stewart became the sole agents for Life-Long pencils in 1933. The clip style suggests this pencil predates this.
At 12.2 cm. in length, it is a full sized, rather slim pencil, a very tactile item. The pencil is constructed in Silver, it is clearly stamped 'Sterling Silver' around the finial. There are small dints around the finial, as shown,but the body of the pencil is ding free with just light usage marks.
The pencil is longitudinally engraved with groups of fine lines and has a blank cartouche.
The mechanism is a 'continuous twist' type, it operates by turning the cap clockwise to expel and anti clockwise to retract the lead. A new lead has been fitted and it works well with a smooth action. Spare leads are stored in the inner barrel, whch also appears to be Silver.